bluuebunny/crossref_metadata_2025 huggingface dataset:
Disparity-Tuned Population Responses from Human Visual Cortex
Authors: Cottereau Benoit R. , McKee Suzanne P. , Ales Justin M. , Norcia Anthony M.
Published: January 2011

We used source imaging of visual evoked potentials to measure neural population responses over a wide range of horizontal disparities (0.5–64 arcmin). The stimulus was a central disk that moved back and forth across the fixation plane at 2 Hz, surrounded either by binocularly uncorrelated dots (disparity noise) or by correlated dots presented in the fixation plane. Both disk and surround were composed of dynamic random dots to remove coherent monocular information. Disparity tuning was measured in five visual regions of interest (ROIs) [V1, human middle temporal area (hMT+), V4, lateral occipital complex (LOC), and V3A], defined in separate functional magnetic resonance imaging scans. The disparity tuning functions peaked between 2 and 16 arcmin for both types of surround in each ROI. Disparity tuning in the V1 ROI was unaffected by the type of surround, but surround correlation altered both the amplitude and phase of the disparity responses in the other ROIs. Response amplitude increased when the disk was in front of the surround in the V3A and LOC ROIs, indicating that these areas encode figure–ground relationships and object convexity. The correlated surround produced a consistent phase lag at the second harmonic in the hMT+ and V4 ROIs without a change in amplitude, while in the V3A ROI, both phase and amplitude effects were observed. Sensitivity to disparity context is thus widespread in visual cortex, but the dynamics of these contextual interactions differ across regions.
GluA2 (GluR2) Regulates Metabotropic Glutamate Receptor-Dependent Long-Term Depression through N-Cadherin-Dependent and Cofilin-Mediated Actin Reorganization
Authors: Zhou Zikai , Hu Jim , Passafaro Maria , Xie Wei , Jia Zhengping
Published: January 2011

The GluA2 (GluR2) subunit is critical for the regulation of AMPA receptor properties and synaptic plasticity, but the underlying mechanisms remain unclear. Here, we demonstrate that GluA2 regulates metabotropic glutamate receptor-dependent long-term depression (mGluR-LTD) through a previously unknown mechanism involving N-cadherin-dependent and cofilin-mediated actin reorganization. We show that GluA2 is indispensable for mGluR-LTD in the hippocampus, and surprisingly this action of GluA2 is mediated by its extracellular domain interaction with N-cadherin. Accordingly, we show that the function of N-cadherin is regulated by and required for mGluR-LTD. Furthermore, we show that the regulatory effect of GluA2/N-cadherin is mediated through activation of Rho GTPase Rac1 and its downstream actin regulator cofilin, and, importantly, the requirement for GluA2/N-cadherin can be overcome by manipulating cofilin. These results provide compelling evidence that the extracellular domain of GluA2 regulates long-lasting synaptic plasticity through a signaling mechanism that is distinct from those used by the other domains of the receptor subunit.
Drosophila taoControls Mushroom Body Development and Ethanol-Stimulated Behavior throughpar-1
Authors: King Ian , Tsai Linus T.-Y. , Pflanz Ralf , Voigt Aaron , Lee Seongsoo , Jäckle Herbert , Lu Bingwei , Heberlein Ulrike
Published: January 2011

In both mammalian and insect models of ethanol-induced behavior, low doses of ethanol stimulate locomotion. However, the mechanisms of the stimulant effects of ethanol on the CNS are mostly unknown. We have identifiedtao, encoding a serine-threonine kinase of the Ste20 family, as a gene necessary for ethanol-induced locomotor hyperactivity inDrosophila. Mutations intaoalso affect behavioral responses to cocaine and nicotine, making flies resistant to the effects of both drugs. We show thattaofunction is required during the development of the adult nervous system and thattaomutations cause defects in the development of central brain structures, including the mushroom body. Silencing of a subset of mushroom body neurons is sufficient to reduce ethanol-induced hyperactivity, revealing the mushroom body as an important locus mediating the stimulant effects of ethanol. We also show that mutations inpar-1suppress both the mushroom body morphology and behavioral phenotypes oftaomutations and that the phosphorylation state of the microtubule-binding protein Tau can be altered by RNA interference knockdown oftao, suggesting thattaoandpar-1act in a pathway to control microtubule dynamics during neural development.
Noninvasive Magnetic Resonance Imaging Detection of Cerebral Amyloid Angiopathy-Related Microvascular Alterations Using Superparamagnetic Iron Oxide Particles in APP Transgenic Mouse Models of Alzheimer's Disease: Application to Passive Aβ Immunotherapy
Authors: Beckmann Nicolau , Gérard Christelle , Abramowski Dorothée , Cannet Catherine , Staufenbiel Matthias
Published: January 2011

Cerebral amyloid angiopathy (CAA) is a common feature of Alzheimer's disease (AD). More advanced stages are accompanied by microhemorrhages and vasculitis. Peripheral blood-borne macrophages are intimately linked to cerebrovascular pathology coincident with AD. Magnetic resonance imaging (MRI) was used to noninvasively study microvascular lesions in amyloid precursor protein transgenic mouse AD models. Foci of signal attenuation were detected in cortical and thalamic brain regions of aged APP23 mice. Their strength and number was considerably enhanced by intravenous administration of iron oxide nanoparticles, which are taken up by macrophages through absorptive endocytosis, 24 h before image acquisition. The number of cortical sites displaying signal attenuation increased with age. Histology at these sites demonstrated the presence of iron-containing macrophages in the vicinity of CAA-affected blood vessels. A fraction of the sites additionally showed thickened vessel walls and vasculitis. Consistent with the visualization of CAA-associated lesions, MRI detected a much smaller number of attenuated signal sites in APP23xPS45 mice, for which a strong presenilin mutation caused a shift toward amyloid β42, thus reducing vascular amyloid. Similar results were obtained with APP24 and APP51 mice, which develop significantly less CAA and microvascular pathology than APP23. In a longitudinal study, we noninvasively demonstrated the reinforced formation of microvascular pathology during passive amyloid β immunotherapy of APP23 mice. Histology confirmed that foci of signal attenuation reflected an increase in CAA-related lesions. Our data demonstrate that MRI has the sensitivity to noninvasively monitor the development of vascular pathology and its possible enhancement by amyloid β immunotherapy in transgenic mice modeling AD.
Spontaneous Action Representation in Smokers when Watching Movie Characters Smoke
Authors: Wagner Dylan D. , Dal Cin Sonya , Sargent James D. , Kelley William M. , Heatherton Todd F.
Published: January 2011

Do smokers simulate smoking when they see someone else smoke? For regular smokers, smoking is such a highly practiced motor skill that it often occurs automatically, without conscious awareness. Research on the brain basis of action observation has delineated a frontoparietal network that is commonly recruited when people observe, plan, or imitate actions. Here, we investigated whether this action observation network would be preferentially recruited in smokers when viewing complex smoking cues, such as those occurring in motion pictures. Seventeen right-handed smokers and 17 nonsmokers watched a popular movie while undergoing functional magnetic resonance imaging. Using a natural stimulus, such as a movie, allowed us to keep both smoking and nonsmoking participants naive to the goals of the experiment. Brain activity evoked by movie scenes of smoking was contrasted with nonsmoking control scenes that were matched for frequency and duration. Compared with nonsmokers, smokers showed greater activity in left anterior intraparietal sulcus and inferior frontal gyrus, regions involved in the simulation of contralateral hand-based gestures, when viewing smoking versus control scenes. These results demonstrate that smokers spontaneously represent the action of smoking when viewing others smoke, the consequence of which may make it more difficult to abstain from smoking.
Dynamic Characterization ofDrosophilaAntennal Olfactory Neurons Indicates Multiple Opponent Signaling Pathways in Odor Discrimination
Authors: French Andrew S. , Torkkeli Päivi H. , Schuckel Julia
Published: January 2011

Opponent signaling refers to processes in which antagonistic signals are produced by different, but closely related, stimuli. It allows enhanced discrimination and more accurate behavioral responses. We explored opponent signaling in theDrosophila melanogasterolfactory system by measuring frequency response functions between odorant concentrations and primary olfactory neuron responses. Random fluctuations in concentration of two aliphatic and two aromatic fruit odorants were used to modulate action potentials from basiconic antennal sensilla. We separated action potentials by two-dimensional cluster analysis using amplitude and cross-correlation with a median action-potential template. Frequency response functions were fitted with either bandpass or second-order low-pass functions and then divided into two polarity groups, excitatory and inhibitory, by fitting the frequency response functions. Cluster analysis gave two, three, or four action potential clusters for each sensillum recording. Sensilla were then grouped by the patterns of response polarities of the individual neurons into four sensillum types, one with four neurons and three with two neurons. All four odorant compounds produced a mixture of excitatory, inhibitory, and null responses in different neurons. Statistical analysis of frequency response parameters for individual odorants gave only weak correlation between dynamics and some neuron types, even when comparing the dynamics of excitatory and inhibitory responses to the same odorant. However, response dynamics were significantly different between aliphatic and aromatic compounds, and between the two aliphatic compounds. Each odorant caused opposing excitatory and inhibitory signals to be sent to the antennal lobe along at least two pairs of axonal pathways.
Remaking Slavery in a Free State: Masters and Slaves in Gold Rush California
Authors: Smith Stacey L.
Published: January 2011

Hundreds of white Southerners traveled to Gold Rush California with slaves. Long after California became a free state in 1850, these masters transplanted economic and social practices that sustained slavery in the American South to the goldfields. At the same time, enslaved people realized that Gold Rush conditions disrupted customary master-slave relationships and pressed for more personal autonomy, better working conditions, and greater economic reward. The result was a new regional version of slavery that was remarkably flexible and subject to negotiation. This fluidity diminished, however, as proslavery legislators passed laws that protected slaveholding rights and vitiated the state's antislavery constitution. California's struggle over bondage highlights the persistence of the slavery question in the Far West after the Compromise of 1850 and illuminates slavery's transformation as it moved onto free soil.
Going "Mad" in Gold Country: Migrant Populations and the Problem of Containment in Pacific Mining Boom Regions
Authors: Hawk Angela
Published: January 2011

Based on archival research conducted in California, British Columbia, and eastern Australia, this essay examines the role of mobility in shaping the institutional experiences of individuals committed or arrested for insanity in the major Pacific mining boom regions of the nineteenth century. Through the transnational story of James "Scotty" Brown, a sailor who escaped from the California State Insane Asylum in time to join the 1858 American migration to the Fraser River goldfields in British Columbia, I demonstrate that instability and flux characterized not only the backgrounds of "mad" migrants, but also their frequent encounters with gold country asylums and jails. Specifically, I argue that these institutions often facilitated the mobility of the individuals that, in principle, they were constructed to "contain."
Detection and Population Estimation for Small-Bodied Fishes in a Sand-Bed River
Authors: Widmer Ann M. , Burckhardt Laura L. , Kehmeier Jon W. , Gonzales Eric J. , Medley C. Nicolas , Valdez Richard A.
Published: January 2011

Multiple-pass removal by use of small-mesh seines within enclosed areas was performed to estimate numbers of nine small-bodied fish species at 17 sites in the Pecos River, New Mexico, during October 2007. Site-level population estimates were most precise for age-0 red shiners Cyprinella lutrensis (coefficient of variation [CV, calculated as SE/mean] = 0.02–0.06) and least precise for age-1 and older plains minnow Hybognathus placitus (CV = 0.03–0.42). Site estimates were expanded to derive species- and age-specific population estimates for 284 km of river, including the full range of the threatened Pecos bluntnose shiner Notropis simus pecosensis (101,131 fish; 95% confidence interval = 76,437–125,825; CV = 0.12). Population estimates and species detection from multiple-pass removal were compared with a closed, comprehensive, single-pass catch rate index obtained on the first pass of the removal estimate (comprehensive catch per effort [C-CPE]) and with an open, single-pass catch rate index (single-pass catch per effort [S-CPE]), where a set of representative mesohabitats was seined in proportion to their availability (mean = 12.6 hauls/site). Compared with removal estimates, C-CPE provided a reliable index of population size for the nine small-bodied species combined (r2 = 0.90, P = 0.010) but did not perform as reliably for adult Pecos bluntnose shiners (r2 = 0.51) or age-0 speckled chub Macrhybopsis aestivalis (r2 = 0.70). On average, C-CPE detected 89% of species at a site, missing predatory species most frequently. By contrast, S-CPE was a poor index of population size for all species (r2 = 0.16, P = 0.010) and detected an average of 52% of species at a site. The S-CPE failed to detect the Rio Grande shiner N. jemezanus at 28.5% of sites, the sand shiner N. stramineus at 41.2% of sites, the Pecos bluntnose shiner at 29.4% of sites, and the speckled chub at 23.5% of sites; all of these are small-boded native species. For applications that require reliable species detection and precise abundance estimates of small-bodied fishes, the multiple-pass removal method is recommended.
Population Viability of Arctic Grayling in the Gibbon River, Yellowstone National Park
Authors: Steed Amber C. , Zale Alexander V. , Koel Todd M. , Kalinowski Steven T.
Published: January 2011

The fluvial Arctic grayling Thymallus arcticus is restricted to less than 5% of its native range in the contiguous United States and was relisted as a category 3 candidate species under the U.S. Endangered Species Act in 2010. Although fluvial Arctic grayling of the lower Gibbon River, Yellowstone National Park, Wyoming, were considered to have been extirpated by 1935, anglers and biologists have continued to report catching low numbers of Arctic grayling in the river. Our goal was to determine whether a viable population of fluvial Arctic grayling persisted in the Gibbon River or whether the fish caught in the river were downstream emigrants from lacustrine populations in headwater lakes. We addressed this goal by determining relative abundances, sources, and evidence for successful spawning of Arctic grayling in the Gibbon River. During 2005 and 2006, Arctic grayling comprised between 0% and 3% of the salmonid catch in riverwide electrofishing (mean < 1%; SE < 1%) and snorkeling (mean = 1%; SE = 1%) surveys; Arctic grayling constituted 0–14% of the salmonid catch obtained by targeted angling (3 of 22 fish; mean = 4%; SE = 5%). Low values of the genetic differentiation index (FST = 0.0021 ± 0.002 [mean ± 95% confidence interval]) between headwater lake and river Arctic grayling indicated that fish from throughout the Gibbon River system probably belonged to the same population. Back-calculated lengths at most ages were similar among all fish, and successful spawning within the Gibbon River below the headwater lakes was not documented. Few Arctic grayling adults and no fry were detected in the Gibbon River, implying that a reproducing fluvial population does not exist there. These findings have implications for future Endangered Species Act considerations and management of fluvial Arctic grayling within and outside of Yellowstone National Park. Our comprehensive approach is broadly applicable to the management of sparsely detected aquatic species worldwide.
Frostbite: experimental and clinical evaluations of treatment
Authors: Heggers J.P. , Phillips L.G. , McCauley R.L. , Robson M.C.
Published: January 2011

Based on experimental and clinical data, this review emphasizes the need for proper treatment of frostbite injuries. Experimentally employed anti-eicosanoid therapy in the modified Weatherly White model enhanced tissue survival, as each agent's inhibitory properties became more specific, when compared to controls. Topical methylprednisolone had a 17.5% tissue survival, while aspirin, Aloe vera cream and methimazole had 22.5%, 28.2% and 34.3% survival, respectively ( p < 0.05). One hundred fifty-four (154) humans were evaluated as to therapeutic modalities; 56 were treated with topical Aloe vera cream and systemic ibuprofen, while 98 were treated with other modalities. Patient demographics were similar. However, hospital stay, tissue loss and morbidity were significantly ( p < 0.001) reduced in the Aloe plus ibuprofen group when compared to the other therapeutic modalities, average 13 days v. 20 days, 79.9% healed v. 32.7% healed, and 7% morbidity v. 32.7% morbidity. Tissue loss from frostbite can be reduced if topical Aloe vera and systemic ibuprofen are employed as adjunctive therapies.
Methods of gas-balance control to be used with a portable hyperbaric chamber in the treatment of high altitude illness
Authors: Gamow R.I. , Geer G.D. , Kasic J.F. , Smith H.M.
Published: January 2011

A portable fabric hyperbaric chamber (Gamow BagTM) has been designed for on site treatment of altitude illness. The chamber includes a manual pumping system, weighs 6.57 kg (14.5 pounds), and can be carried in a backpack. A laboratory study was undertaken to document safety, subject comfort and gas retention characteristics of the chamber. The chamber is designed to be used in one of three different modes: pump mode, bladder mode, and oxygen-scrubber mode. In the pump mode, 521 min–1 of fresh air is continuously supplied via an air pump. Using this technique, ten healthy volunteers were placed in the chamber for 90 min at pressures up to 16.0 kPa (120 mmHg) above ambient pressure. Ambient CO2 and O2 levels were found to be less than 1% and more than 20%, respectively. Testing the bladder mode, six subjects exhaled via a nasal mask into a latex bladder, not allowing CO2 to accumulate in the chamber. Using this mode, the pumping rate can be decreased by a factor of ten, a great advantage when the pumper is working at altitudes above 5792 m (19000 ft). In the oxygen-scrubber mode, O2 was continuously added via a pressure regulator. CO2 accumulation was eliminated with a high efficiency CO2 scrubber made of LiOH. One pound of scrubber and 150 1 of pressurized O2 can keep an average person in an atmosphere of 21% O2 with less than 1% CO2for 6 h. In this mode, all pumping, except the initial pressurization of the bag, is eliminated.
Submersion incidents: a review of 39 cases and development of the submersion outcome score
Authors: Anderson K.C. , Roy T.M. , Danzl D.F.
Published: January 2011

The optimal treatment of the submersion victim continues to be revised and debated. Accurate analysis of therapeutic response to resuscitation after submersion will require a validated prognostic scale. The patient population is very heterogenous, with few cases presenting at many sites. We selected 11 potential predictive variables to be reviewed in 39 submersion incidents. These included the five variables comprising the Orlowski score. Three ‘physiologic’ variables were identified which, in combination, also predict neurologic outcome: pH less than or equal to 7.10, PaO2/PAO2 ratio less than or equal to 0.35, and anion gap greater than or equal to 15 mEq−1. Refinement and validation of a submersion outcome score limited to variables accurately ascertained at presentation will facilitate comparison of treatment protocols.
Delayed use of antivenin in black widow spider (Latrodectus mactans) envenomation
Authors: Allen R.C. , Norris R.L.
Published: January 2011

The management of a victim of widow spider envenomation remains controversial because the use of specific antivenin to treat isolated, painful muscle spasms is not widely accepted. We report a case of black widow spider ( Latrodectus mactans) envenomation which resulted in muscle spasms, pain, and elevated blood pressure. The symptoms were refractory to treatment with calcium gluconate, diazepam and methocarbamol, and were temporarily decreased by use of meperidine. All symptoms dramatically resolved following use of antivenin 46 h after envenomation. A brief review of widow spider envenomation is presented.
Wilderness medicine: a clinical introduction for medical students
Authors: Cordes D.H. , Rea D.F. , Gerhauser R.
Published: January 2011

We offered a wilderness medicine selective seminar to first-year medical students at the University of Arizona. Twenty students took the selective, which was designed as an introduction and to stimulate interest in acquiring more in-depth knowledge of the field. Separate sessions were held on specific subject areas: high altitude; wilderness injuries; field water disinfection and diarrheal illnesses; toxic and survival plants; envenomation; underwater medicine; and heat and cold stress. A mountain climb was offered as an optional field experience. Student evaluation indicated the goals of the selective were achieved more than adequately by content and methods. We view the selective as a successful attempt to introduce wilderness medicine to medical students. However, a teaching approach for advanced students could include a more comprehensive approach.
Corpses released from glacier ice: glaciological and forensic aspects
Authors: Ambach W. , Ambach E. , Tributsch W. , Henn R. , Unterdorfer H.
Published: January 2011

Glaciological and forensic aspects of six corpses released from glacier ice during summer 1991 are discussed in detail. The times of immersion in glacier ice of fatally injured persons can vary from several years to several centuries. The corpses are transported along a flow line beneath the surface of the glacier and emerge on the surface only after reaching the ablation area. Immersion times of more than 1000 years are possible with corpses buried in stagnant or dead ice areas. Adipocere and mummification are characteristic changes to soft tissues and organs. The Homo tyrolensis found on Hauslabjoch (elevation 3200 m (10500 ft), Oetztal Alps, Austria) was determined to be 5000 years old.
Cougar attack: case report of a fatality
Authors: Conrad Lily
Published: January 2011

The case of an 18-year-old adult male killed by a cougar (mountain lion) is presented. Cougars rarely attack humans, but inflict serious injury. Large bite or claw wounds, frequently to the head and neck, require emergency medical management with attention to deep structure injury, as well as potential Pasteurella multocida or rabies infection. Cougar–human interactions are increasing as rural housing developments and recreation in wilderness areas expand. Understanding cougar predator–prey behavior may help prevent attacks and injuries, particularly to children.
Travel-related diseases: injury and infectious disease prevention
Authors: Shandera Wayne X.
Published: January 2011

To counsel prospective travelers, physicians should familiarize themselves with risks and exposures associated with travel. The most common causes of travelers’ mortality and morbidity, respectively, are accidents and infections. Precautions to prevent accidents include limiting alcohol use, providing vehicle-specific safety precautions, and recognizing special risks in areas traveled. A knowledge of immunization regulations and endemic diseases can facilitate counseling travelers. Booster immunizations against childhood vaccine-preventable diseases may be needed. Gamma globulin prophylaxis should be used to prevent hepatitis A in areas where fecal contamination of foodstuffs occurs. Since effective immunotherapy for travelers’ diarrhea does not exist, practical advice regarding food and water exposure is essential. Among the elderly, attention should be directed toward the effects of travel on age-specific medical problems (e.g., cardiovascular events) which may occur more often in this age group than do infections. Other recommendations should be tailored to the specific activities of a given traveler.
Submersion injury complicated by hyperthermia in a kayaker wearing a dry suit
Authors: Brody Allan J. , Mitchell Connie , Springer Martin
Published: January 2011

Environmental suits are designed to protect the user from hypothermia due to cold water exposure. We describe a case of a kayaker who suffered a submersion injury while wearing an environmental dry suit, was transported from the cold water environment to the emergency department, and on arrival was found to be hyperthermic. We discuss the pathophysiology of thermal derangement and submersion injury, and the thermodynamics of environmental suits. We suggest the mechanism for this unexpected and previously unreported complication. We conclude with possible means of avoiding this complication.
The first ascent of Mount Everest, 1953: the solution of the problem of the ‘last thousand feet’
Authors: Ward Michael
Published: January 2011

Pugh's pioneering work at high altitude on Cho Oyu in 1952 dictated the framework for the first ascent of Everest in 1953. He demonstrated that a flow rate of 4 litres of oxygen per minute in the open circuit sets was necessary to provide a boost to performance sufficient to climb Everest from a high camp, at 8600 m, with a safe return to the South Col (8000 m) in one day.

Sleeping oxygen mitigated high altitude deterioration, as did Pugh's insistence on a very high fluid intake to combat dehydration. Together with adequate protection from the cold, which was less severe than predicted, these strategies resulted in all climbers who went above 8000 m being in good physical and mental condition.
Wilderness related musculoskeletal injury: role of bone scintigraphy
Authors: Orr Liston , Taylor Andrew
Published: January 2011

Musculoskeletal pain is a common sequela of wilderness related activities. X-ray analysis of persistent musculoskeletal pain often reveals no specific etiology. Nuclear medicine bone scintigraphy has the ability to detect several types of abnormalities which can be missed by plain film techniques. These abnormalities include: 1) stress fracture, 2) enthesopathy, 3) occult fracture. Scintigraphic diagnosis of these injuries can lead to proper and timely treatment while a negative bone scan can effectively rule out osseous injury.
Carbon monoxide hazard in sub-Antarctic exploration
Authors: Gill Rowland M.F.
Published: January 2011

During a sub-Antarctic expedition, petrol stoves were used for cooking inside tents and snow-holes (snow caves). The carbon monoxide hazard from the use of petrol stoves was assessed by measuring atmospheric levels with direct-reading indicator tubes (Draeger tubes). Levels up to 300 ppm were recorded, higher than previous field experiments have shown. The levels recorded were unlikely to have affected the exercise capacity of expedition members or to have had other serious effects. Direct-reading tubes were a simple and effective means of measurement. One episode of acute serious hazard occurred and is described, but the atmospheric carbon monoxide level was not recorded. It is concluded that the most important hazard from carbon monoxide under mountaineering and exploration conditions is that of acute fatal poisoning.
Epidemiologic basis for the practice of travel medicine
Authors: Steffen Robert , Lobel Hans O.
Published: January 2011

The major health risks for travelers to developing countries include injuries, malaria, hepatitis A, hepatitis B, rabies, AIDS and travelers’ diarrhea. Most illnesses can be avoided by use of preventive measures including use of seatbelts in cars, hygienic measures and use of effective immunization and chemoprophylaxis. Practitioners of travel medicine need to know the health risks that confront travelers in order to advise which preventive measures should be used. Most available data apply to travelers visiting developing countries.
Serious Physalia (Portuguese man o’war) stings: implications for scuba divers
Authors: Burnett Joseph W. , Fenner Peter J. , Kokelj Franco , Williamson John A.
Published: January 2011

The objective of this study was to describe a serious jellyfish envenomation in a scuba diver by an Atlantic Physalia physalis, to review the related literature and to recommend safe diving practices that may reduce the risk of serious jellyfish envenomation in divers. A healthy scuba diving instructor wearing a full wetsuit and gloves but no hood ascended from a night dive and surfaced directly under a large Atlantic Physalia jellyfish. He suffered multiple severe stings to the unprotected areas of his face and neck. He developed acute subjective respiratory distress with hyperventilation, muscle pain and spasms, and impaired consciousness en route to hospital, more than 10 min following envenomation. He recovered quickly in hospital with oxygen, aminophylline and intravenous fluid administration. Delayed recovery of the envenomated skin took several weeks and serology was positive for Physalia venom antibodies. Full protective clothing (e.g. a full, long sleeved wetsuit, plus gloves and hood when appropriate) should be worn by scuba divers on all dives. Ascent routines in diving should include looking directly upwards at the surface with one wetsuited arm outstretched towards the surface throughout the ascent. Removal of tentacles should not be attempted by the diver until he or she has exited from the water.
Wilderness Medical Society: The First Dozen Years
Authors: Bowman Warren D.
Published: January 2011

This manuscript has been prepared as the tenth Annual Meeting of the Wilderness Medical Society approaches. It consists of a chronological history of the society from its founding in 1982 as a “Mom and Pop” organization headquartered in Dr. Edward Geehr's study to its current status as a national organization with a part-time executive director, two full-time employees, access to the resources of the American College of Sports Medicine, an international journal, a quarterly newsletter, and over 2800 members. Its educational programs now include annual summer and winter national scientific meetings plus at least one annual national specialty meeting, local and regional meetings, curricula for medical school wilderness medicine electives and prehospital wilderness emergency care courses, position papers on relevant topics, and teaching aids, including slide collections. It has an active program for sponsoring research in wilderness medicine and promotes the health of travelers and global health through its Environmental Council.
Life-threatening anaphylaxis following envenomation by two different species of Crotalidae
Authors: Ryan Kenneth C. , Martin Caravati E.
Published: January 2011

Anaphylactic reaction to snake venom occurs rarely but is a risk in those victims with previous exposure to venomous snakes and their venom. We present the case of a herpetologist who suffered acute, life-threatening anaphylaxis on two separate occasions following envenomation by two different species of rattlesnake. On both occasions the patient received treatment for anaphylaxis within minutes of being bitten and responded well. Administration of crotalidae antivenin was unnecessary. Snake venom is a heterologous mixture of proteins and other chemicals and is able to provoke immune sensitization to its components in humans. Antigenic similarities are often present in venoms of different species. IgE and IgG have been demonstrated in sera from patients who have suffered snake venom anaphylaxis. This case testifies to the immunogenicity of rattlesnake venom across species.
Experimental brown spider bite in the guinea pig: Results of treatment with dapsone or hyperbaric oxygen
Authors: Beilman Greg J. , Winslow Christopher L. , Teslow Timothy W.
Published: January 2011

The brown recluse spider (Loxosceles reclusa) is a common inhabitant of the central United States. Loxoceles envenomation is a cause of significant medical problems, causing a necrotic skin lesion that often becomes a problem wound. Treatment of the skin lesion is controversial, with no current widely accepted therapy. The effects of treatment with hyperbaric oxygen or dapsone on brown spider bites were studied using guinea pigs. Progression and healing of experimental brown spider bites were measured in animals treated or pretreated with dapsone or hyperbaric oxygen and in controls. There was a significant decrease in lesion size in animals pretreated with hyperbaric oxygen at days 3,5, and 6 as compared to dapsone-pretreated animals or untreated controls. However, there were no differences noted between groups when treatment was begun 36 h after envenomation. There was a nonsignificant increase ( p = 0.12) noted in myeloperoxidase levels from lesions of animals pretreated with hyperbaric oxygen. No other differences in levels of catalase, glutathione, or superoxide dismutase activity were noted between treatment groups. These results suggest that hyperbaric oxygen may have potential in the treatment of brown spider bites; however, further study is necessary to prove its efficacy.
Human tick bite records in a United States Air Force population, 1989–1992: implications for tick-borne disease risk
Authors: Campbell Brian S. , Bowles David E.
Published: January 2011

Reports of tick parasitism were recorded for US Air Force personnel ( n = 410) from 30 states and the District of Columbia. Of 462 ticks involved in attacks on people, the lone star tick, Amblyomma americanum, and the American dog tick, Dermacentor variabilis, were the most common species represented (34.2% and 34.0%, respectively). Two vectors of Lyme disease, Ixodes pacificus and Ixodes scapularis (including the former Ixodes dammini) also parasitized people but were less common (1.7% and 9.1%, respectively). In addition, 34 (7.3%) brown dog ticks, Rhipicephalus sanguineus, were identified from human hosts. Most ticks submitted for identification were adults (66.5%) and nymphs (29.1%). Larvae were submitted infrequently (<5%). Of those specimens examined for feeding status, 50.0% had blood-fed to some degree. Patients from which ticks were removed were predominantly male (56.8%) and ranged in age from 1 to 76 years with 55.3% (n = 152) being under 20 years. The head and neck area and the lower extremities were the most common sites of attachment by ticks (37.7% and 24.3%, respectively), but ticks were found attached on other areas of the body also, including the trunk, upper extremities, buttocks, and groin. Most ticks (65.5%) bit their victims during May, June, or July, but parasitism occurred during all months of the year. Our data suggest that people from all age groups and from across the United States are vulnerable to parasitism by ticks and, potentially, tick-borne diseases.
Palladium-Based Alloy Membranes for Separation of High Purity Hydrogen from Hydrogen-Containing Gas Mixtures
Authors: Burkhanov By Gennady S. , Gorina Nelli B. , Kolchugina Natalia B. , Roshan Nataliya R. , Slovetsky Dmitry I. , Chistov Evgeny M.
Published: January 2011

Palladium-based alloys with yttrium, copper, ruthenium or indium additions were investigated. Their specific hydrogen permeability, strength, linear thermal expansion in hydrogen and corrosion resistance in a number of gas media were determined. This allowed effective membrane elements to be developed using membranes made from these alloys, which are used for the separation of high purity hydrogen from hydrogen-containing gas mixtures. Membrane elements with 93.5 wt% palladium-6 wt% indium-0.5 wt% ruthenium alloy membranes were developed by the authors’ research group, and their technical characteristics are described.
Nitrogen Use Efficiency of Irrigated Corn for Three Cropping Systems in Nebraska
Authors: Wortmann C. S. , Tarkalson D. D. , Shapiro C. A. , Dobermann A. R. , Ferguson R. B. , Hergert G. W. , Walters D.
Published: January 2011

Nitrogen use efficiency (NUE) is of economic and environmental importance. Components of NUE were evaluated at in 32 irrigated corn (Zea mays L.) trials conducted across Nebraska with different N rates and where the previous crop was either corn (CC), drybean (Phaseolus vulgaris L.) (CD), or soybean [Glycine max (L.) Merr.] (CS). The mean grain yield with adequate nutrient availability was 14.7 Mg ha−1 When no N was applied, measured soil properties and irrigation water N accounted for <20% of the variation in plant nitrogen uptake (UN). Mean fertilizer N recovery in aboveground biomass was 74% at the lowest N rate compared with 40% at the highest N rate, a mean of 64% at the economically optimal nitrogen rate (EONR), and least with CD. Agronomic efficiency of fertilizer N averaged 29 kg grain kg−1 N at EONR and was also least with CD. Partial factor productivity of N averaged 100 kg grain kg−1 N at EONR, and was greater with CS compared with CC and CD. After harvest, residual soil nitrate nitrogen (RSN) in the 0‐ to 1.2‐m depth ranged from 21 to 121 kg ha−1 and increased with N rate. Mean RSN was 88, 59, and 59 kg ha−1 for CD, CC, and CS, respectively. High corn yields can be achieved with high NUE and low RSN by management to maximize profitability in consideration of yield potential, and by applying N at the right amount and time.
Effects of Soybean Seed Size on Weed Competition
Authors: Place G. T. , Reberg‐Horton S. C. , Carter T. E. , Smith A. N.
Published: January 2011

Organic soybean [Glycine max (L.) Merr.] producers must rely on various, nonherbicidal tactics for weed management. Increased soybean seed size may be one method to increase the competitiveness of the soybean canopy. Soybean varieties Hutcheson, NC‐Roy, and NC‐Raleigh were separated into four or five seed size classes. Seed sizes ranged from 5.15 to 6.75 mm diam. This range of seed size resulted in seed weights of 10 to 20 g per 100 seed. Each seed size class was grown in weedy and weed‐free conditions at Kinston, NC during 2007 and 2008 and at Plymouth, NC during 2008. Redroot pigweed (Amaranthus retroflexus L.) overseeding was done to create uniform weed densities. Increasing soybean seed size resulted in greater soybean canopy coverage with the greatest effect at 3 weeks after emergence (WAE) (P < 0.001, P = 0.003, and P < 0.001 at Kinston 2007, Kinston 2008, and Plymouth 2008, respectively) compared with 5 WAE (P = 0.02, P = 0.07, and P = 0.02 at Kinston 2007, Kinston 2008, and Plymouth 2008, respectively). Plants from larger seed sizes had more soybean biomass in all sites when grown with weeds, but in only two sites under weed‐free conditions. Larger seed size improved soybean competitiveness by increasing petiole length and plant height. In the two sites with higher weed population densities, planting larger soybean seed reduced weed biomass at 7 WAE. Results suggest that use of larger planting seed may improve weed control in organic soybean production.
Seed Yield and Loss of Dry Bean Cultivars under Conventional and Direct Harvest
Authors: Eckert Fernando R. , Kandel Herman J. , Johnson Burton L. , Rojas‐Cifuentes Gonzalo A. , Deplazes Chad , Vander Wal Albert J. , Osorno Juan M.
Published: January 2011

North Dakota is the leading producer of dry beans (Phaseolus vulgaris L.) in the United States. In order to remain competitive, growers need to find ways to optimize yields and minimize input costs. Direct harvest may decrease equipment investment, harvest time, and operational costs when compared with conventional methods. However, direct harvest is often associated with reduced seed yield and quality. Experiments were conducted at four environments in North Dakota to evaluate the harvest efficiency of nine dry bean cultivars representing three market classes. Seed yield, seed loss, and other agronomic/morphological traits were measured using a split plot design. Harvest method and cultivar were consistently the most important factors contributing to seed yield and seed loss. Seed yield was significantly greater (830 kg ha−1) with the conventional method and seed loss was significantly greater (23.2%) under direct harvest. For conventional harvest, there was no difference in seed yield among cultivars within a market class. However, under direct harvest, one pinto (Lariat) and two black bean (T‐39 and Eclipse) cultivars showed the highest yield. There were no differences among the navy cultivars for seed yield. Lariat was the most efficient cultivar across and within both harvest methods, with the best combination of highest yield (2232 kg ha−1) and lowest seed loss (11.1%). None of the morphological traits measured had a strong association with seed yield or seed loss. Results indicate that for optimal yields, growers need to select a cultivar with the best harvest efficiency possible, in addition to other factors.
Efficiency of Controlled‐Release Urea for a Potato Production System in Quebec, Canada
Authors: Ziadi Noura , Grant Cynthia , Samson Nicolas , Nyiraneza Judith , Bélanger Gilles , Parent Léon‐Étienne
Published: January 2011

Proper N management is essential to prevent N losses and ensure high potato (Solanum tuberosum L.) yield and quality. Controlled‐release urea (CRU) could increase nitrogen use efficiency (NUE) by matching the release of N with potato N uptake. This 3‐yr study conducted in Quebec, Canada, compared four treatments, namely an unfertilized control (0 N), calcium ammonium nitrate (CAN) application at rates of 150 kg N ha−1 (150CAN) and 200 kg N ha−1 (200CAN), and CRU application at a rate of 150 kg N ha−1 (150CRU). The effects of treatments were assessed on potato yield, specific gravity, NUE, and chlorophyll meter readings (CMR) for two cultivars (Goldrush and Chieftain) along with soil nitrate adsorbed on anion exchange membranes (NO3AEMs). Marketable yield and the yield of jumbo and medium size classes significantly increased with N fertilization up to 150 kg N ha−1, and yields were higher with 150CRU than with 150CAN or 200CAN. Nitrogen fertilization increased CMR, but had no effect on specific gravity. The CRU continually released more nitrate during the growing season as indicated by higher NO3AEMs values, and had higher NUE compared with other treatments. Relative yield (RY) was significantly related by linear‐plateau functions to CMR and NO3AEMs measured 40 to 50 d after planting, hence providing the critical values of 41.9 for CMR and 15 μg cm−2 d−1 for NO3AEMs, above which the probability of a yield response to additional N is low. Controlled‐release urea is a promising N source for increasing the yield and NUE of potatoes produced in eastern Canada.
An Analysis of Yield Component Changes for New vs. Old Soybean Cultivars
Authors: Kahlon Charanjit S. , Board James E. , Kang Manjit S.
Published: January 2011

Reasons for the gradual genetic yield improvement (10–30 kg ha−1yr−1) reported for soybean [Glycine max (L.) Merr.] during decades of cultivar development are not clearly understood. Identification of mechanisms for the yield improvement would aid in providing indirect selection criteria for streamlining cultivar development. Our objective was to identify yield components responsible for yield improvement in 18 public southern cultivars released between 1953 and 1999. The study was done at the Ben Hur Research Farm near Baton Rouge, LA (30°N Lat) during 2007 and 2008, plus a validation study in 2009. Experimental design was a randomized complete block with four replications and one factor (cultivar). In the 2007–2008 study, 18 cultivars released across the 1953–1999 period were selected. Three old and three new cultivars were used for the 2009 validation study. Data were obtained on yield, seed m−2, seed size, seed per pod, pod m−2, pod per reproductive node (a reproductive node is one having at least one pod having at least one seed), reproductive node m−2, percent reproductive nodes and node m−2 Data were analyzed by ANOVAR and mean separation. Regression and path analyses were also done between yield and yield components, year of release and yield components, and among yield components themselves. Results of the 2007–2008 study indicated that yield differences were sequentially controlled by node m−2, reproductive node m−2, pod m−2, and seed m−2 However, node m−2 was not as accurate at distinguishing low and high‐yielding cultivars as the other three yield components and its role in yield formation was not substantiated in the validation study. A possible indirect selection criterion for yield during cultivar development is reproductive node m−2
Growth and Yield Responses of Soybean to Row Spacing and Seeding Rate
Authors: Cox William. J. , Cherney Jerome H.
Published: January 2011

Some growers in northern latitudes plant soybean [Glycine max (L.) Merr.] with a row crop planter in 0.38 m rows, but an economic analysis concluded that drilled soybean in rows <0.25 m was optimum in the North‐Central United States. We planted two varieties in 0.19, 0.38, and 0.76 m rows at 321,000; 371,000; 420,000; and 469,000 seeds ha−1 in New York in 2008 and 2009 to evaluate how soybean compensates to wide rows or low seeding rates in the Northeast United States. Soybean had limited compensation in biomass, pods, and seeds plant−1 at wider rows so row spacing had linear responses for biomass accumulation (598, 554, and 497 g m−2 in 0.19, 0.38. and 0.76 m rows, respectively) and leaf area index (LAI, 3.64, 3.47, and 3.16) at seed initiation; pod (1012, 935, and 875 pods m−2) and seed density (2272, 2230, and 2072 seeds m−2, respectively) at harvest; and yield (3.37, 3.12, and 2.86 Mg ha−1, respectively). Compensation in biomass, pods, and seeds plant−1 at lower seeding rates resulted in similar biomass accumulation (528–570 g m−2), LAI (3.38–3.46), pod (921–965 pods m−2), and seed densities (2123 to 2234 seeds m−2) across seeding rates. Nevertheless, yield showed a quadratic response to seeding rate (3.04, 3.25, and 3.12 Mg ha−1 at 321,000; 420,000; and 469,000 seeds ha−1, respectively) with no row spacing interaction. Soybean compensated more at lower seeding rates than at wider rows, but field‐scale studies are being conducted to evaluate the economics of both practices.