Archive for September 2007
Study Shows The Power Of Attraction
Whether we are seeking a mate or sizing up a potential rival, good-looking people capture our attention nearly instantaneously and render us temporarily helpless to turn our eyes away from them, according to a new Florida State University study.
“It’s like magnetism at the level of visual attention,” said Jon Maner, an assistant professor of psychology at FSU, who studied the role mating-related motives can play in a psychological phenomenon called attentional adhesion. His findings are published in the September issue of the Journal of Personality and Social Psychology.
The paper, “Can’t Take My Eyes Off You: Attentional Adhesion to Mates and Rivals,” is one of the first to show how strongly, quickly and automatically we are attuned to attractive people, he said. FSU graduate students Matthew Gailliot, D. Aaron Rouby and Saul Miller co-authored the study.
In a series of three experiments, Maner and his colleagues found that the study participants, all heterosexual men and women, fixated on highly attractive people within the first half of a second of seeing them. Single folks ogled the opposite sex, of course, but those in committed relationships also checked people out, with one major difference: They were more interested in beautiful people of the same sex.
“If we’re interested in finding a mate, our attention gets quickly and automatically stuck on attractive members of the opposite sex,” Maner said. “If we’re jealous and worried about our partner cheating on us, attention gets quickly and automatically stuck on attractive people of our own sex because they are our competitors.”
Maner’s research is based on the idea that, through processes of biological evolution, our brains have been designed to strongly and automatically latch on to signs of physical attractiveness in others in order to both find a mate and guard him or her from potential competitors.
“These kinds of attentional biases can occur completely outside of our conscious awareness,” he said.
Biology or not, this phenomenon is fraught with potential romantic peril. For example, even some people in committed relationships had difficulty pulling their attention away from images of attractive people of the opposite sex. And fixating on images of perceived romantic rivals could contribute to feelings of insecurity.
Modern technology has enhanced these pitfalls. Although there are people of striking beauty in real life, singer Frankie Valli’s pronouncement that “you’re just too good to be true” may be the case when it comes to images in movies and magazines or on the Internet.
“It may be helpful to try to minimize our exposure to these images that have probably been ‘doctored,'” Maner said. “We should pay attention to all of the regular-looking people out in the world so that we have an appropriate standard of physical beauty. This is important because too much attention to ultra-attractive people can damage self-esteem as well as satisfaction with a current romantic partner.”
In the experiments, study participants — 120 people in the first study and 160 and 162 in the second and third studies, respectively — completed questionnaires to determine the extent to which they were motivated to seek out members of the opposite sex. They then took part in a series of “priming” activities before they were shown photos of highly attractive men, highly attractive women, average-looking men and average-looking women.
After a photo of one of the faces flashed in one quadrant of a computer screen, the participants were required to shift their attention away from that face to somewhere else on the screen. Using a precise measure of reaction time, Maner found that it took the participants longer to shift their attention away from the photos of the highly attractive people.
Maner said he was surprised that his studies showed little differences between the sexes when it came to fixating on eye-catching people.
“Women paid just as much attention to men as men did to women,” he said. “I was also surprised that jealous men paid so much attention to attractive men. Men tend to worry more about other men being more dominant, funny or charismatic than they are. But when it comes to concerns about infidelity, men are very attentive to highly attractive guys because presumably their wives or girlfriends may be too.”
J Pers Soc Psychol. 2007 Sep;93(3):389-401.
Can’t take my eyes off you: Attentional adhesion to mates and rivals.
Department of Psychology, Florida State University, Tallahassee, FL 32306-4301, USA. email@example.com
In 3 experiments, mating primes interacted with functionally relevant individual differences to guide basic, lower order social perception. A visual cuing method assessed biases in attentional adhesion–a tendency to have one’s attention captured by particular social stimuli. Mate-search primes increased attentional adhesion to physically attractive members of the opposite sex (potential mates) among participants with an unrestricted sociosexual orientation but not among sexually restricted participants (Studies 1 and 2). A mate-guarding prime increased attentional adhesion to physically attractive members of one’s own sex (potential rivals) among participants who were concerned with threats posed by intrasexual competitors but not among those less concerned about such threats (Study 3). Findings are consistent with a functionalist approach to motivation and social cognition and highlight the utility of integrating evolutionary and social cognitive perspectives. (c) 2007 APA, all rights reserved
Changes in the immune system may explain why social factors like loneliness are linked to an increased risk of heart disease, viral infections and cancer.
It’s already known that a person’s social environment can affect their health, with those who are socially isolated–that is, lonely suffering from higher mortality than people who are not.
Now, in the first study of its kind, published in the current issue of the journal Genome Biology, UCLA researchers have identified a distinct pattern of gene expression in immune cells from people who experience chronically high levels of loneliness. The findings suggest that feelings of social isolation are linked to alterations in the activity of genes that drive inflammation, the first response of the immune system. The study provides a molecular framework for understanding why social factors are linked to an increased risk of heart disease, viral infections and cancer.
Having previously established that lonely people suffer from higher mortality than people who are not, researchers are now trying to determine whether that risk is a result of reduced social resources, such as physical or economic assistance, or from the biological impact of social isolation on the function of the human body.
“What this study shows is that the biological impact of social isolation reaches down into some of our most basic internal processes the activity of our genes.” said Steve Cole, an associate professor of medicine in the division of Hematology-Oncology at the David Geffen School of Medicine, and a member of the UCLA Cousins Center for Psychoneuroimmunology.
“We found that changes in immune cell gene expression were specifically linked to the subjective experience of social distance,” said Cole, who is also a member of the Jonsson Comprehensive Cancer Center. “The differences we observed were independent of other known risk factors, such as health status, age, weight, and medication use. The changes were even independent of the objective size of a person’s social network.”
Cole and colleagues at UCLA and the University of Chicago used DNA microarrays to survey the activity of all known human genes in white blood cells from 14 individuals in the Chicago Health, Aging, and Social Relations Study. Six participants scored in the top 15 percent of the UCLA Loneliness Scale, a widely used measure of loneliness that was developed in the 1970s; the others scored in the bottom 15 percent. The researchers found 209 gene transcripts (the first step in the making of a protein) were differentially expressed between the two groups, with 78 being overexpressed and 131 underexpressed. “Leukocyte (white blood cell) gene expression appears to be remodelled in chronically lonely individuals,” said. Cole.
Genes overexpressed in lonely individuals included many involved in immune system activation and inflammation. But interestingly, several other key gene sets were underexpressed, including those involved in antiviral responses and antibody production. “These findings provide molecular targets for our efforts to block the adverse health effects of social isolation,” said Cole.
“We found that what counts at the level of gene expression is not how many people you know, it’s how many you feel really close to over time.” In the future, he said, the transcriptional fingerprint they’ve identified might become useful as a ‘biomarker’ to monitor interventions designed to reduce the impact of loneliness on health.
Genome Biol. 2007 Sep 13;8(9):R189 [Epub ahead of print]
Social regulation of gene expression in human leukocytes.
ABSTRACT: BACKGROUND: Social environmental influences on human health are well established in the epidemiology literature, but their functional genomic mechanisms are unclear. The present study analyzed genome-wide transcriptional activity in people who chronically experienced high versus low levels of subjective social isolation (loneliness) to assess alterations in the activity of transcription control pathways that might contribute to increased adverse health outcomes in social isolates. RESULTS: DNA microarray analysis identified 209 genes that were differentially expressed in circulating leukocytes from 14 high- versus low-lonely individuals, including up-regulation of genes involved in immune activation, transcription control, and cell proliferation, and down-regulation of genes supporting mature B lymphocyte function and type I interferon response. Promoter-based bioinformatic analyses showed under-expression of genes bearing anti-inflammatory glucocorticoid response elements (GREs; p = 0.032) and over-expression of genes bearing response elements for pro-inflammatory NF-kB/Rel transcription factors (p = 0.011). This reciprocal shift in pro- and anti-inflammatory signaling was not attributable to differences in circulating cortisol levels, or to other demographic, psychological, or medical characteristics. Additional transcription control pathways showing differential activity in bioinformatic analyses included the CREB/ATF, JAK/STAT, IRF1, C/EBP, Oct, and GATA pathways. CONCLUSIONS: These data provide the first indication that human genome-wide transcriptional activity is altered in association with a social epidemiological risk factor. Impaired transcription of glucocorticoid response genes and increased activity of pro-inflammatory transcription control pathways provide a functional genomic explanation for elevated risk of inflammatory disease in individuals who experience chronically high levels of subjective social isolation.
HIV patients with declining platelet counts appear to be at increased risk for HIV–associated dementia.
“Human immunodeficiency virus–associated dementia (HIV-D) is a syndrome encompassing a spectrum of cognitive, behavioral and motor deficits that usually has an insidious onset and a chronic progressive course,” the authors write as background information in the article. Therapies leading to longer life for HIV patients have paradoxically increased the prevalence of this condition. Identifying biological markers for the development of HIV–associated dementia is critical both for diagnosing the disorder and for understanding its underlying mechanisms.
Lynn M. Wachtman, D.V.M., M.P.H., of Bloomberg School of Public Health, The Johns Hopkins University School of Medicine, Baltimore, and colleagues studied 396 patients with advanced HIV who were recruited for this prospective study between 1998 and 2003. Participants were examined every six months and completed mental and physical evaluations.
Blood samples were also collected and assessed for platelet count (the number of clotting cells in the blood), hemoglobin levels, CD4 lymphocyte count (a measure of certain types of white blood cells, which reflects the state of the immune system) and plasma HIV RNA levels (which indicate the amount of “viral load,” and predict HIV progression).
After a median (midpoint) follow-up of 31.1 months, 40 participants developed HIV–associated dementia. A decline in platelet count from baseline was associated with the development of dementia within six to 12 months. “Those HIV-infected individuals with a decline in platelets from baseline values at this lagged time point had a two-fold increased risk of dementia” in several different analyses, the authors write. The specific timing of the association indicates that the levels of circulating platelets fluctuate as HIV–associated dementia develops, they note.
“Further analyses indicated that decline from baseline platelet levels was associated with a five- to six-fold increased risk of dementia during the first two years of follow-up, but it was not associated with an increased risk of dementia after two years,” the authors continue. “It is possible that individuals who do not progress rapidly to neurologic compromise differ in respect to immune activation, treatment adherence or virologic control relative to those who develop dementia more rapidly.”
“Because CD4 cell counts and HIV RNA levels have proven not to be predictive of HIV–associated dementia, it is important to investigate alternative serum and hematologic markers,” the authors conclude. “Should these markers be routinely measured in a clinical setting, such as platelet counts, they may prove useful for patient management. This study identifies a significant association between platelet decline and incident HIV–associated dementia.” Further study of platelet levels during HIV–associated dementia may lead both to a specific marker for the development of HIV–associated dementia and a better understanding of how the disease develops.
Arch Neurol. 2007 Sep;64(9):1264-72.
Platelet decline: an avenue for investigation into the pathogenesis of human immunodeficiency virus associated dementia.
Department of Neurology, The Johns Hopkins University School of Medicine, 600 N Wolfe St, Baltimore, MD 21287-7609. firstname.lastname@example.org.
BACKGROUND: The identification of biomarkers identifying onset of human immunodeficiency virus-associated dementia (HIV-D) is critical for diagnosis and the elucidation of pathophysiologic pathways. OBJECTIVE: To examine the association between platelet decline from baseline and HIV-D. DESIGN: Prospective cohort study within the North-East AIDS Dementia cohort. SETTING: Four participating referral centers in the United States. PARTICIPANTS: A total of 396 subjects with advanced human immunodeficiency virus (HIV) infection recruited between 1998 and 2003 and undergoing serial neurologic assessments. Eligibility criteria required CD4 cell counts less than 200/muL or less than 300/muL with evidence of cognitive impairment. A cohort subset without prevalent HIV-D at baseline and without incident HIV-D at the visit immediately after baseline was analyzed (n = 146). Main Outcome Measure Time to first diagnosis of HIV-D. RESULTS: After a median follow-up of 31.1 months, 40 subjects developed HIV-D. Platelet decline from baseline was associated with the development of HIV-D when examined as a time-dependent variable lagged by 6 to 12 months before outcome (multivariate hazard ratio [HR], 2.39; 95% confidence interval [CI], 1.14-5.02; P = .02). This association was stronger during the first 2 years of follow-up (multivariate HR, 6.76; 95% CI, 2.36-19.41; P < .001) than during later years (multivariate HR, 0.94; 95% CI, 0.33-2.67; P = .90). CONCLUSIONS: These results suggest that individuals with declining platelet counts are at greater risk for HIV-D and that the dynamics of circulating platelets vary with respect to the temporal progression of HIV-D. This highlights an avenue to be explored in the understanding of HIV-D pathogenesis.
By Wendy Barnaby
Psychological factors can make people more likely to suffer physical illness, but cognitive behavioural therapy can help sufferers manage their condition.
“People often pigeonhole diseases as being biological or psychological, but in fact they’re often a complex mixture of both,” Professor Rona Moss-Morriss of the University of Southampton told the BA Festival of Science on Monday.
She and her colleagues studied 1000 people who contracted either glandular fever or food poisoning. They wanted to see who would go on to develop irritable bowel syndrome (IBS).
The symptoms of IBS are severe stomach pain, with diarrhoea or constipation or both. The people with food poisoning were more likely to develop IBS, perhaps because both conditions affect the stomach. But psychological factors were important, too.
The researchers asked the patients how they felt when they had food poisoning, what they did and what they believed. They found that those who were more stressed, and who had very high expectations of themselves, were more likely to develop IBS.
Having high expectations manifested itself in an “all-or-nothing” pattern of behaviour, in which people would try to ignore the symptoms to fulfil their normal obligations, only to collapse in bed, try to get up too quickly, and collapse again.
The researchers have submitted a study for publication in which they used the psychological intervention called cognitive behavioural therapy (CBT) to help people with IBS. “It appears to be a promising approach,” they said.
Their new study follows one in which some IBS patients were given CBT along with an anti-spasmodic drug, mebeverine, while others received mebeverine alone. Those who received CBT as well saw their symptoms improve.
Professor Trudie Chalder of Kings College London said a study of patients with type 1 diabetes would give “good news” when it is published shortly. Her results were, she said, “extremely promising.”
She used CBT to address people’s beliefs about their diabetes. For example, some people will say: “There’s nothing I can do to control my diabetes because it’s a biological disease which I have no control over.” Having used CBT to challenge such beliefs, Professor Chalder aimed to improve people’s blood sugar levels by encouraging them to exercise regularly and eat a healthy diet.
The 2007 IUCN Red List of Threatened Species – Photo Gallery
The photographs presented here represent a selection of species from the 2007 IUCN Red List and were contributed from a range of sources including IUCN SSC Specialist Group members and ARKive. For a wider selection of threatened species imagery, please see ARKive (www.arkive.org), an online multi-media of the world’s species.
|The Baiji (Lipotes vexillifer) is probably the most threatened cetacean species in the world. The last documented sighting of the species was in 2002 and in November/December 2006 surveys failed to find any individuals of the species in its native Yangtze River in China. The species has been listed as Critically Endangered since 1996, but in 2007 it was reassessed as Critically Endangered and flagged as Possibly Extinct. Entanglement in fishing gear, electric fishing practices, boat propeller strikes, dam construction, river siltation (from deforestation and agricultural expansion), and pollution have all contributed to the dramatic declines of this species. Further survey work is essential to confirm whether this species still exists or if it is indeed now extinct; for example, a reported sighting of the species in August 2007 requires confirmation. Photo © Mark Carwardine / NHPA / Photoshot. Photo provided by ARKive.|
|The Western Gorilla (Gorilla gorilla) was uplisted from Endangered to Critically Endangered in 2007 after the Western Lowland Gorilla (G. g. gorilla) subspecies, suffered a population decline of more than 60% since the early 1980s. Hunting and deaths caused by Ebola were the main causes of this decline and both these threats continue to affect the Western Lowland Gorilla population. An investigation of Ebola outbreaks has revealed that if this disease continues at its current rate and trajectory, then the Western Lowland Gorilla abundance in all current protected areas could decline by 45% between 1992 and 2011. The Western Lowland Gorilla makes up most of the current Western Gorilla population. The other subspecies, Cross River Gorilla (G. g. diehli), was first listed as Critically Endangered in 1996. With fewer than 200 mature adults remaining in this population and ongoing habitat loss, it is still a highly threatened subspecies and remains in the Critically Endangered category. Photo © M. Watson / www.ardea.com. Photo provided by ARKive.|
|Sumatran Orangutan (Pongo abelii) is listed as Critically Endangered. Endemic to the island of Sumatra in Indonesia, this ape has suffered a population decline of more than 80% over the last 75 years. The species is seriously threatened by logging (both legal and illegal), wholesale conversion of forest to agricultural land, and oil palm plantations, and fragmentation by roads. Animals are also illegally hunted and captured for the international pet trade but this appears to be more a symptom of habitat conversion, as orangutans are killed as pests when they raid fruit crops at the forest edge. Most orang-utans occur outside of protected areas. After a period of relative stability, pressure on these forests is increasing once again as a result of the recent peace accord, and a dramatic increase in demand for timber and other natural resources after the December 2004 tsunami. Photo © Anup Shah / naturepl.com. Photo provided by ARKive.|
|Speke’s Gazelle (Gazella spekei) is endemic to the Horn of Africa. Formerly widespread in the open barren grasslands of Somalia and the central coastal region, this gazelle currently inhabits a 20-40 km wide grassland plain that extends along the Indian Ocean coastline of Somalia. The species was rare in eastern Ethiopia in the mid-1980s, and extreme hunting pressure was on the verge of eliminating the species from the area even then. Political instability and periodic civil and military conflicts over the past 20 years in Somalia have resulted in a prevalence of weapons, over-exploitation of wildlife, and lack of protection for wildlife. An illegal wildlife trade, including in antelopes, has developed in Somalia during the last few years. Drought and overgrazing due to increasing numbers of domestic livestock have also negatively affected habitat. This gazelle has declined by more than 50% since 1988 and hence its status has been changed from Vulnerable to Endangered. Photo © Mark Bowler / NHPA / Photoshot. Photo provided by ARKive.|
|White-headed Vulture (Trigonoceps occipitalis) was uplisted from Least Concern to Vulnerable in 2007. This vulture has an extremely large range in sub-Saharan Africa. It has declined rapidly in parts of West Africa since the early 1940s and in southern Africa is now largely confined to protected areas. It is estimated that the global population is around 2,600-4,700 pairs (7,000-12,500 mature individuals). Reductions in populations of medium-sized mammals and wild ungulates, as well as habitat conversion throughout its range best explain current decline. Additional threats are indirect poisoning by baits set to kill jackals in small-stock farming areas, although this species is less susceptible than other vultures owing to its broad diet. Exploitation for the international trade in raptors also poses a threat. Photo © Nigel J. Dennis / NHPA / Photoshot. Photo provided by ARKive.|
|The Egyptian Vulture (Neophron percnopterus) has a large range, including southern Europe, Africa, and central Asia to northern India and Nepal. Nevertheless, this species has been uplisted from Least Concern to Endangered on the 2007 Red List following a very recent and extremely rapid population decline in India combined with severe long term declines in Europe (>50% over the last three generations) and West Africa, plus ongoing declines through much of the rest of its African range, owing to a variety of threats. Declines in parts of Africa are likely to have been driven by loss of wild ungulate populations and overgrazing in some areas by livestock. Disturbance, lead poisoning (from gun-shot) and collision with powerlines are currently impacting European populations. In India, it appears that the veterinary drug Diclofenac is driving the recent rapid declines. In Morocco at least, the species is taken for use in traditional medicine. Photo © Bernard Castelein / naturepl.com. Photo provided by ARKive.|
|The Mauritius Parakeet (Psittacula eques) survives only on Mauritius; it is now extinct on Réunion. This parakeet’s past decline and contracting distribution was caused by severe destruction and degradation of its native habitat. From the 1970s to the mid-1980s only 10 or so birds were known. However, after a period of successful breeding, the population size had grown to 16-22 by 1993-1994, and 59-73 wild birds by 1998. The rapid increase in population size since 1995 is due to intensive management of the wild population and discovery of previously unknown breeding birds. In January 2000 the population size was 106-126 wild individuals. This bird occupies only around 40 km2 of remnant native upland forest and uses only around 50% of this area regularly. The remaining habitat continues to be highly degraded by cyclones, influences of past forestry practices, spread of introduced plants and animals (e.g., pigs, Rusa Deer). As a result of the increased population size, P. eques was downlisted from Critically Endangered in 2007, but it is still threatened and is now listed as Endangered. Photo © Malcolm Burgess. Photo provided by ARKive.|
|Gharial (Gavialis gangeticus) was uplisted from Endangered to Critically Endangered in 2007. Its historic range extended from the Indus River (Pakistan) to the Irrawaddy River (Myanmar). Today three widely separated breeding subpopulations are left in India, and one in Nepal. Its decline is mainly due to habitat loss through, for example, rivers being dammed and exploited for human uses, expansion of crop and livestock agricultural areas. Along with habitat loss, current serious threats to the species include entanglement in fishing nets and hunting; parts of the Gharial are still used in some traditional medicines, and its eggs are eaten by tribal people. Photo © G. & H. Denzau / naturepl.com. Photo provided by ARKive.|
|The Blunt-nosed Leopard Lizard (Gambelia sila) is endemic to California in the United States and is listed as Endangered. Its distribution and abundance have both been greatly reduced due to habitat loss to urbanization, water development projects, and agricultural development; intensive mineral development, off-road vehicle activity, pesticides, overgrazing, and flooding. The species has been eliminated from 94% of its original range since the mid-1800s and its currently known occupied range includes scattered parcels of undeveloped land on the floor of the San Joaquin Valley and in the foothills of the Coast Range. There are not many more than a few dozen distinct subpopulations. Photo © Patrick Briggs.|
|The Santa Catalina Island Rattlesnake (Crotalus catalinensis) is endemic to Isla Santa Catalina, a 40 km2 island in the Gulf of California, Mexico. It was formerly a common species, but has probably declined, principally due to over-collecting and the past impact of feral cats. The species is listed as Critically Endangered. The current main threat to this species is the loss of individuals by killing and illegal collection. Santa Catalina Island is home to 10 reptile species, of which seven are endemic. Island endemic reptile species are often the most wanted in the illegal trade market, and hence are usually more threatened. The passive behaviour of this species makes it easy to catch or kill. Population declines of its main prey, the Catalina Deermouse (Peromyscus slevini) is also an important threat. Photo © Ingo Arndt / naturepl.com. Photo provided by ARKive.|
|Phelsuma antanosy is a Critically Endangered gekko known from only two forests on Madagascar. Currently, there is a maximum of 9 km2 of suitable habitat available for this species. The population is severely fragmented and it is threatened by the destruction of its remaining forest habitat. Although new protected areas have been created within its range, illegal forest degradation continues. There are future plans to begin mining operations for ilmenite (used for creating titanium) in the area occupied by one of the remaining P. antanosy subpopulations, which threatens the future of this subpopulation Photo © Richard Jenkins.|
|The Coachella Valley Fringe-toed Lizard (Uma inornata) is endemic to southern California in the United States, and is restricted to the Coachella Valley in Riverside County. Its small historical range (around 839 km2) is now much reduced due to agricultural and urban development; its habitat has been degraded by stabilization of dunes by planted windbreaks. At least 80-90% of this lizard’s habitat has been lost. Roads and railroad cuttings fragment the remaining habitat. Sand migration due to winds may affect the long-term survival of this species at two of the sections of the Coachella Valley Preserve, as the dunes may be moving out of the conservation areas. The species is listed as Endangered. Photo © William Flaxington.|
|Historically the range of the Giant Gartersnake (Thamnophis gigas) included much of the floor of the Central Valley (Sacramento and San Joaquin valleys) of California, United Sates. This Vulnerable species apparently is now extirpated from most of its range in the San Joaquin Valley due to loss and fragmentation of wetland habitats. Habitat loss and degradation remain the greatest threats to the survival of this snake. In some areas, predation by and competition with introduced species, parasitism, and road kills may also be serious threats. Photo © Gary Nafis.|
|the Panamint Alligator Lizard (Elgaria panamintina) is known only from California in the United States. This Vulnerable species is known from several locations in desert mountains of Inyo and Mono counties, California. The known area of occupancy is very small (probably less than 5 km2). Most known locations are in canyon riparian zones below permanent springs. All but a few of the known subpopulations occur on private lands and are currently at risk from mining, feral and domestic livestock grazing, and increasing off-road vehicle activity. Photo © Gary Nafis.|
|The Banggai Cardinalfish (Pterapogon kauderni) is a rare example of a marine fish with an extremely limited geographic range. This Endangered fish is endemic to the Banggai Archipelago in Indonesia; its total range area is around 5,500 km2, however the maximum potential habitat available within this range is about 34 km2. The Banggai Cardinalfish is highly prized in the aquarium trade and has been heavily exploited since 1994, resulting in an 89% reduction in population size from the start of aquarium fishery in 1995-1996 to 2007. The present total population size is between 1.8 and 2.2 million individuals, but an estimated minimum of 700,000 to 900,000 fish are extracted every year for the aquarium trade. Significant destruction of its habitat due to dynamite fishing, recently discovered diseases and algal blooms which affect extensive areas of the species. coral field habitat are also major threats. Photo © B. Jones & M. Shimlock / NHPA / Photoshot. Photo provided by ARKive.|
|The Humphead Parrotfish (Bolbometopon muricatum) is listed on the 2007 Red List as Vulnerable. This Indo-Pacific marine fish is now considered globally rare, with local densities negatively correlated with fishing pressure and with suspected local extinctions at some localities. Underwater surveys across its range have either failed to detect this species or have detected only rare individuals. It is considered abundant only on the Great Barrier Reef and at Rowley Shoals (Australia). This is a large-sized, long-lived species with low replacement rates and high vulnerability to fishing pressure. It is an important coral reef species, maintaining ecosystem resilience; the species consumes reef carbonate; its absence highlights the potential for marked changes in ecosystem function. The main threat to the Humphead Parrotfish is fishing, particularly spearfishing. Photo © Georgette Douwma / naturepl.com. Photo provided by ARKive.|
|Floreana Coral (Tubastraea floreana) is a rare endemic coral to the Galápagos Archipelago. Before 1983, the species was known from only six sites. However, after the 1982-1983 El Niño event, it was not reported from any site until the early 1990s when three colonies were observed and photographed at Cousins, near Santiago. These colonies were observed each year until 2001 when they disappeared. Despite targeted searches throughout the Archipelago, the only colonies found recently were located at Gardner Islet, near Floreana in 2004. The dramatic reduction in this coral’s distribution immediately after the 1982-83 El Niño event suggests that this mortality resulted from the event. Presumably climate change is an additional threat. It is listed on the 2007 Red List as Critically Endangered. Photo © P. Humann / www.fishid.com. Photo provided by ARKive.|
|Wellington’s Solitary Coral (Rhizopsammia wellingtoni), endemic to the Galápagos Archipelago, was recorded from three sites prior to 1984. This coral was extremely abundant at Tagus Cove, Isabela, but all colonies have apparently disappeared since the 1982-83 El Niño event. It is possible that the species is now extinct, but further surveys are required to confirm this. Hence, it is listed on the 2007 Red List listed as Critically Endangered (Possibly Extinct). The threat of El Niño has not ceased, so if it still exists, there is likely to be continuing decline in the range of this species. Photo © P. Humann / www.fishid.com. Photo provided by ARKive.|
|Although apricots are widely cultivated in many countries, the Wild Apricot (Armeniaca vulgaris) is considered very rare in its natural range (China, Kazakhstan, Kyrgyzstan and Uzbekistan). In Kazakhstan it is only known from three localities. This species is the progenitor of all cultivated apricots, but construction, development of tourism resorts, cutting for fuel wood, harvesting of fruit and the collection of germplasm by both national and international plant breeding companies threaten the remaining trees in the wild. This species is therefore listed as Endangered. Photo © Damiano Avanzato.|
|The “Galápagos Kelp (Eisenia galapagensis) is an endemic species from the Galápagos Islands. Prior to the 1980s, the species was recorded from multiple sites across the central and western archipelago, but currently it is known only from western Fernandina and southwestern Isabela, in spite of targeted surveys for the species. There has been an estimated population decline of 30 to 50% every ten years for the last 30 years. There have been widespread declines in algal populations in the Galápagos because of an increase in density of grazing sea urchins and other herbivores following overexploitation of predators, along with El Niño disturbances, probably exacerbated by climate change. The species is assessed as Vulnerable. Photo © Sean Connell, University of Adelaide|
Life on Earth is disappearing fast and will continue to do so unless urgent action is taken, according to the 2007 IUCN Red List of Threatened Species.
There are now 41,415 species on the IUCN Red List and 16,306 of them are threatened with extinction, up from 16,118 last year. The total number of extinct species has reached 785 and a further 65 are only found in captivity or in cultivation.
One in four mammals, one in eight birds, one third of all amphibians and 70% of the world’s assessed plants on the 2007 IUCN Red List are in jeopardy.
Julia Marton-Lefèvre, Director General of the World Conservation Union (IUCN), said: “This year’s IUCN Red List shows that the invaluable efforts made so far to protect species are not enough. The rate of biodiversity loss is increasing and we need to act now to significantly reduce it and stave off this global extinction crisis. This can be done, but only with a concerted effort by all levels of society.”
The IUCN Red List of Threatened Species is widely recognized as the most reliable evaluation of the world’s species. It classifies them according to their extinction risk and brings into sharp focus the ongoing decline of the world’s biodiversity and the impact that mankind is having upon life on Earth.
Jane Smart, Head of IUCN’s Species Programme, said: “We need to know the precise status of species in order to take the appropriate action. The IUCN Red List does this by measuring the overall status of biodiversity, the rate at which it is being lost and the causes of decline.
“Our lives are inextricably linked with biodiversity and ultimately its protection is essential for our very survival. As the world begins to respond to the current crisis of biodiversity loss, the information from the IUCN Red List is needed to design and implement effective conservation strategies – for the benefit of people and nature.”
Decline of the great apes
A reassessment of our closest relatives, the great apes, has revealed a grim picture. The Western Gorilla (Gorilla gorilla) has moved from Endangered to Critically Endangered, after the discovery that the main subspecies, the Western Lowland Gorilla (Gorilla gorilla gorilla), has been decimated by the commercial bushmeat trade and the Ebola virus. Their population has declined by more than 60% over the last 20-25 years, with about one third of the total population found in protected areas killed by the Ebola virus over the last 15 years.
The Sumatran Orangutan (Pongo abelii) remains in the Critically Endangered category and the Bornean Orangutan (Pongo pygmaeus) in the Endangered category. Both are threatened by habitat loss due to illegal and legal logging and forest clearance for palm oil plantations. In Borneo, the area planted with oil palms increased from 2,000 km2 to 27,000 km2 between 1984 and 2003, leaving just 86,000 km2 of habitat available to the species throughout the island.
First appearance of corals on the IUCN Red List
Corals have been assessed and added to the IUCN Red List for the very first time. Ten Galápagos species have entered the list, with two in the Critically Endangered category and one in the Vulnerable category. Wellington’s Solitary Coral (Rhizopsammia wellingtoni) has been listed as Critically Endangered (Possibly Extinct). The main threats to these species are the effects of El Niño and climate change.
In addition, 74 seaweeds have been added to the IUCN Red List from the Galápagos Islands. Ten species are listed as Critically Endangered, with six of those highlighted as Possibly Extinct. The cold water species are threatened by climate change and the rise in sea temperature that characterizes El Niño. The seaweeds are also indirectly affected by overfishing, which removes predators from the food chain, resulting in an increase of sea urchins and other herbivores that overgraze these algae.
Yangtze River Dolphin listed as Critically Endangered (Possibly Extinct)
After an intensive, but fruitless, search for the Yangtze River Dolphin, or Baiji, (Lipotes vexillifer) last November and December, it has been listed as Critically Endangered (Possibly Extinct). The dolphin has not been placed in a higher category as further surveys are needed before it can be definitively classified as Extinct. A possible sighting reported in late August 2007 is currently being investigated by Chinese scientists. The main threats to the species include fishing, river traffic, pollution and degradation of habitat.
India and Nepal’s crocodile, the Gharial (Gavialis gangeticus) is also facing threats from habitat degradation and has moved from Endangered to Critically Endangered. Its population has recently declined by 58%, from 436 breeding adults in 1997 to just 182 in 2006. Dams, irrigation projects, sand mining and artificial embankments have all encroached on its habitat, reducing its domain to 2% of its former range.
This year the total number of birds on the IUCN Red List is 9,956 with 1,217 listed as threatened. Vultures in Africa and Asia have declined, with five species reclassified on the IUCN Red List. In Asia, the Red-headed Vulture (Sarcogyps calvus) moved from Near Threatened to Critically Endangered while the Egyptian Vulture (Neophron percnopterus) moved from Least Concern to Endangered. The rapid decline in the birds over the last eight years has been driven by the drug diclofenac, used to treat livestock.
In Africa, three species of vulture have been reclassified, including the White-headed Vulture (Trigonoceps occipitalis), which moved from Least Concern to Vulnerable, the White-backed Vulture (Gyps africanus) and Rüppell’s Griffon (Gyps rueppellii), both moved from Least Concern to Near Threatened. The birds’ decline has been due to a lack of food, with a reduction in wild grazing mammals, habitat loss and collision with power lines. They have also been poisoned by carcasses deliberately laced with insecticide. The bait is intended to kill livestock predators, such as hyenas, jackals and big cats, but it also kills vultures.
North American reptiles added
After a major assessment of Mexican and North American reptiles, 723 were added to the IUCN Red List, taking the total to 738 reptiles listed for this region. Of these, 90 are threatened with extinction. Two Mexican freshwater turtles, the Cuatro Cienegas Slider (Trachemys taylori) and the Ornate Slider (Trachemys ornata), are listed as Endangered and Vulnerable respectively. Both face threats from habitat loss. Mexico’s Santa Catalina Island Rattlesnake (Crotalus catalinensis) has also been added to the list as Critically Endangered, after being persecuted by illegal collectors.
Plants in peril
There are now 12,043 plants on the IUCN Red List, with 8,447 listed as threatened. The Woolly-stalked Begonia (Begonia eiromischa) is the only species to have been declared extinct this year. This Malaysian herb is only known from collections made in 1886 and 1898 on Penang Island. Extensive searches of nearby forests have failed to reveal any specimens in the last 100 years.
The Wild Apricot (Armeniaca vulgaris), from central Asia, has been assessed and added to the IUCN Red List for the first time, classified as Endangered. The species is a direct ancestor of plants that are widely cultivated in many countries around the world, but its population is dwindling as it loses habitat to tourist developments and is exploited for wood, food and genetic material.
Banggai Cardinalfish heavily exploited by aquarium trade
Overfishing continues to put pressure on many fish species, as does demand from the aquarium trade. The Banggai Cardinalfish (Pterapogon kauderni), which is highly prized in the aquarium industry, is entering the IUCN Red List for the first time in the Endangered category. The fish, which is only found in the Banggai Archipelago, near Sulawesi, Indonesia, has been heavily exploited, with approximately 900,000 extracted every year. Conservationists are calling for the fish to be reared in captivity for the aquarium trade, so the wild populations can be left to recover.
These highlights from the 2007 IUCN Red List are merely a few examples of the rapid rate of biodiversity loss around the world. The disappearance of species has a direct impact on people’s lives. Declining numbers of freshwater fish, for example, deprive rural poor communities not only of their major source of food, but of their livelihoods as well.
Species loss is our loss
Conservation action is slowing down biodiversity loss in some cases, but there are still many species that need more attention from conservationists. This year, only one species has moved to a lower category of threat. The Mauritius Echo Parakeet (Psittacula eques), which was one of the world’s rarest parrots 15 years ago, has moved from Critically Endangered to Endangered. The improvement is a result of successful conservation action, including close monitoring of nesting sites and supplementary feeding combined with a captive breeding and release programme.
The IUCN Red List of Threatened Species classifies species according to their extinction risk. It is a searchable online database containing the global status and supporting information on more than 41,000 species. Its primary goal is to identify and document the species most in need of conservation attention and provide an index of the state of biodiversity.
The IUCN Red List threat categories are the following, in descending order of threat:
- Extinct or Extinct in the Wild;
- Critically Endangered, Endangered and Vulnerable: species threatened with global extinction;
- Near Threatened: species close to the threatened thresholds or that would be threatened without ongoing specific conservation measures;
- Least Concern: species evaluated with a low risk of extinction;
- Data Deficient: no evaluation because of insufficient data.
Critically Endangered (Possibly Extinct): This is not a new Red List category, but is a flag developed to identify those Critically Endangered species that are in all probability already Extinct but for which confirmation is required (for example, through more extensive surveys being carried out and failing to find any individuals).
The total number of species on the planet is unknown; estimates vary between 10 – 100 million, with 15 million species being the most widely accepted figure. 1.7 – 1.8 million species are known today.
People, either directly or indirectly, are the main reason for most species’ decline. Habitat destruction and degradation continues to be the main cause of species’ decline, along with the all too familiar threats of introduced invasive species, unsustainable harvesting, over-hunting, pollution and disease. Climate change is increasingly recognized as a serious threat, which can magnify these dangers.
Key findings from major analyses to date include:
- The number of threatened species is increasing across almost all the major taxonomic groups.
- IUCN Red List Indices, a new tool for measuring trends in extinction risk are important for monitoring progress towards the 2010 target. They are available for birds and amphibians and show that their status has declined steadily since the 1980s. An IUCN Red List Index can be calculated for any group which has been assessed at least twice.
- Most threatened birds, mammals and amphibians are located on the tropical continents – the regions that contain the tropical broadleaf forests which are believed to harbour the majority of the Earth’s terrestrial and freshwater species.
- Of the countries assessed, Australia, Brazil, China and Mexico hold particularly large numbers of threatened species.
- Estimates vary greatly, but current extinction rates are at least 100-1,000 times higher than natural background rates.
- The vast majority of extinctions since 1500 AD have occurred on oceanic islands, but over the last 20 years, continental extinctions have become as common as island extinctions.
Physicists at UC Riverside have created molecular positronium, an entirely new object in the laboratory. Briefly stable, each molecule is made up of a pair of electrons and a pair of their antiparticles, called positrons.
The ultra-high vacuum target chamber, where the intense positron pulse is implanted into the porous silica film. The magnet coils carry a current of 1000 amps for a few hundred milliseconds to generate the strong magnetic field needed to compress the positron beam. (Credit: David Cassidy, UC-Riverside)
The research paves the way for studying multi-positronium interactions — useful for generating coherent gamma radiation — and could one day help develop fusion power generation as well as directed energy weapons such as gamma-ray lasers. It also could help explain how the observable universe ended up with so much more matter than “antimatter.”
The researchers made the positronium molecules by firing intense bursts of positrons into a thin film of porous silica, which is the chemical name for the mineral quartz. Upon slowing down in silica, the positrons were captured by ordinary electrons to form positronium atoms.
Positronium atoms, by nature, are extremely short-lived. But those positronium atoms that stuck to the internal pore surfaces of silica, the way dirt particles might cling to the inside surface of the holes in a sponge, lived long enough to interact with one another to form molecules of positronium, the physicists found.
“Silica acts in effect like a useful cage, trapping positronium atoms,” said David Cassidy, the lead author of the research paper and an assistant researcher working in the laboratory of Allen Mills, a professor of physics, the research paper’s coauthor. “This is the first step in our experiments. What we hope to achieve next is to get many more of the positronium atoms to interact simultaneously with one another — not just two positronium atoms at a time.”
When an electron meets a positron, their mutual annihilation may ensue or positronium, a briefly stable, hydrogen-like atom, may be formed. The stability of a positronium atom is threatened again when the atom collides with another positronium atom. Such a collision of two positronium atoms can result in their annihilation, accompanied by the production of a powerful and energetic type of electromagnetic radiation called gamma radiation, or the creation of a molecule of positronium, the kind Cassidy and Mills observed in their lab.
“Their research is giving us new ways to understand matter and antimatter,” said Clifford M. Surko, a professor of physics at UC San Diego, who was not involved in the research. “It also provides novel techniques to create even larger collections of antimatter that will likely lead to new science and, potentially, to important new technologies.”
Matter, the “stuff” that every known object is made of, and antimatter cannot co-exist close to each other for more than a very small measure of time because they annihilate each other to release enormous amounts of energy in the form of gamma radiation. The apparent asymmetry of matter and antimatter in the visible universe is an unsolved problem in physics.
Currently, antimatter finds use in medicine where it helps identify diseases with the Positron Emission Tomography or PET scan.
Cassidy and Mills plan to work next on using a more intense positron source to generate a “Bose-Einstein condensate” of positronium — a collection of positronium atoms that are in the same quantum state, allowing for more interactions and gamma radiation. According to them, such a condensate would be necessary for the development of a gamma-ray laser.
Nature 449, 195-197 (13 September 2007) | doi:10.1038/nature06094; Received 11 June 2007; Accepted 17 July 2007
The production of molecular positronium
- Department of Physics and Astronomy, University of California, Riverside, California 92521-0413, USA
It has been known for many years that an electron and its antiparticle, the positron, may together form a metastable hydrogen-like atom, known as positronium or Ps (ref. 1). In 1946, Wheeler speculated2 that two Ps atoms may combine to form the di-positronium molecule (Ps2), with a binding energy3 of 0.4 eV. More recently, this molecule has been studied theoretically4; however, because Ps has a short lifetime and it is difficult to obtain low-energy positrons in large numbers, Ps2 has not previously been observed unambiguously5. Here we show that when intense positron bursts are implanted into a thin film of porous silica, Ps2 is created on the internal pore surfaces. We found that molecule formation occurs much more efficiently than the competing process of spin exchange quenching, which appears to be suppressed in the confined pore geometry. This result experimentally confirms the existence of the Ps2 molecule and paves the way for further multi-positronium work. Using similar techniques, but with a more intense positron source, we expect to increase the Ps density to the point where many thousands of atoms interact and can undergo a phase transition to form a Bose–Einstein condensate6. As a purely leptonic, macroscopic quantum matter–antimatter system this would be of interest in its own right, but it would also represent a milestone on the path to produce an annihilation gamma-ray laser7.
The “Great Firewall of China,” used by the government of the People’s Republic of China to block users from reaching content it finds objectionable, is actually a “Panopticon” that encourages self-censorship through the perception that users are being watched, rather than a true firewall, according to researchers at the University of New Mexico and the University of California Davis.
Photo: UNM researcher Jed Crandall, School of Engineering
The researchers are developing an automated tool, called ConceptDoppler, to act as a weather report on changes in Internet censorship in China. ConceptDoppler uses mathematical techniques to cluster words by meaning and identify keywords that are likely to be blacklisted.
Many countries carry out some form of Internet censorship. Most rely on systems that block specific web sites or web addresses, said Earl Barr, a graduate student in computer science at UC Davis who is an author on the paper. China takes a different approach by filtering web content for specific keywords and selectively blocking web pages.
In 2006, a team at the University of Cambridge, England discovered that when the Chinese system detects a banned word in data traveling across the network, it sends a series of three “reset” commands to both the source and the destination. These “resets” effectively break the connection. But they also allow researchers to test words and see which ones are censored.
Jed Crandall, an assistant professor of Computer Science at the University of New Mexico’s School of Engineering and former UC Davis graduate, UC Davis graduate students Daniel Zinn, Michael Byrd, and Earl Barr and independent researcher Rich East sent messages to internet addresses within China containing a variety of different words that might be subject to censorship.
If China’s censorship system were a true firewall, most blocking would take place at the border with the rest of the Internet, Barr said. But the researchers found that some messages passed through several routers before being blocked.
A firewall should also block all mentions of a banned word or phrase, but banned words reached their destinations on about 28 percent of the tested paths, Byrd said. Filtering was particularly erratic at times of heavy internet use.
The words used to probe the Chinese internet were not selected at random.
“If we simply bombarded the Great Firewall with random words, we would waste resources and time,” Zinn said.
The researchers took the Chinese version of Wikipedia, extracted individual words and used a mathematical technique called Latent Semantic Analysis to work out the relationships between different words. If one of the words was censored within China, they could look up which other closely-related words are likely to be blocked as well.
Examples of words tested by the researchers and found to be banned included references to the Falun Gong movement and the protest movements of 1989; Nazi Germany and other historical events; and general concepts related to democracy and political protest.
“Imagine you want to remove the history of the Wounded Knee massacre from the Library of Congress,” Crandall said. “You could remove ‘Bury my Heart at Wounded Knee’ and a few other selected books, or you could remove every book in the entire library that contains the word ‘massacre.”’
By analogy, Chinese Internet censorship based on keyword filtering is the equivalent of the latter — and indeed, the keyword “massacre” (in Chinese) is on the blacklist.
Because it filters ideas rather than specific websites, keyword filtering stops people from using proxy servers or “mirror” websites to evade censorship. But because it is not completely effective all the time, it probably acts partly by encouraging self-censorship, Barr said. When users within China see that certain words, ideas and concepts are blocked most of the time, they might assume that they should avoid those topics.
The original panopticon was a prison design developed by the English philosopher Jeremy Bentham in the eighteenth century. Bentham proposed that a central observer would be able to watch all the prisoners, while the prisoners would not know when they were being watched.
The work will be presented at the Association for Computing Machinery Computer and Communications Security Conference in Alexandria, Va., Oct. 29-Nov. 2, 2007.