1,440 research outputs found
Guest Editorial: Message to Publishers--We Need Expanded Role Models in Reading Materials
A letter from the editor
Survival and Nesting Habitat use by Sichuan and Ring-necked Pheasants Released in Ohio
Author Institution: Ohio Dept of Natural Resources, Division of Wildlife, Olentangy Wildlife Research Station, Ashley, OHRing-necked pheasant (Phasianus colchicus) populations in the Midwestern United States have declined drastically since World War II. Population numbers in Ohio have leveled off since the establishment of the Conservation Reserve Program (CRP); however, a return to historically abundant ring-necked pheasant populations is unlikely with current land-use practices. Studies by the Michigan
Department of Natural Resources (DNR) of released Sichuan pheasants (P. c. strauchi), a subspecies of the ring-necked pheasant, suggested that Sichuans may nest in woody cover, a trait that could reduce
agriculture-related nest losses common to ring-necked pheasants and potentially increase pheasant populations. We released over 2,000 Sichuan pheasants (962 females, 1,116 males) and 208 ring-necked pheasants (24 females, 84 males) in central Ohio, United States, in early April 1993-96. Survival and habitat use before, during, and after the nesting season were evaluated for a sample of hens from each subspecies
through the use of radio-telemetry. Survival rates (range = 0.05-0.15) and apparent nest success (38% and 50% for Sichuan and ring-necked nests, respectively) were not different between the subspecies. The
largest source of mortality for both subspecies was predation (71-84% and 65-88%, for Sichuan and ring-necked hens, respectively). Most nests, 85% of Sichuan and 81% of ring-necked, were located in
upland herbaceous, upland shrub/scrub, and hay macro-habitat types. Nests of both subspecies were within 16 m of an edge, surrounded by few woody stems (median = 0.25/m2) and dense herbaceous cover (1,450 and 1,130 stems/m2, Sichuan and ring-necked nests, respectively). Sichuan hens selected a higher proportion of forbs (37.5% and 15.0%, Sichuan and ring-necked, respectively) and ring-necked hens selected a higher proportion of grass (17.5% and 37.5%, Sichuan and ring-necked, respectively) within 1.0 m2 of the nest (P †0.010). Population survey indices suggested that a self-sustaining Sichuan pheasant
population was not established
The Role of Spokesperson in Ambiguous and Complex Crises: The CDC and Anthrax
This study evaluates the role of spokespersons in complex organizations facing ambiguous crises. Specifically, the Centers for Disease Control and Preventionâs (CDC) response to the anthrax crisis in 2001 is offered as a case study. A content analysis of the print media coverage of the anthrax crisis reveals that many claiming affiliation with the CDC spoke on behalf of the organization, resulting in what appeared to be a fragmented CDC message. The study concludes that the CDCâs failure to provide a central spokesperson contributed to the ambiguity of the situation
Non-contrast renal magnetic resonance imaging to assess perfusion and corticomedullary differentiation in health and chronic kidney disease
AIMS
Arterial spin labelling (ASL) MRI measures perfusion without administration of contrast agent. While ASL has been validated in animals and healthy volunteers (HVs), application to chronic kidney disease (CKD) has been limited. We investigated the utility of ASL MRI in patients with CKD.
METHODS
We studied renal perfusion in 24 HVs and 17 patients with CKD (age 22-77 years, 40% male) using ASL MRI at 3.0T. Kidney function was determined using estimated glomerular filtration rate (eGFR). T1 relaxation time was measured using modified look-locker inversion and xFB02;ow-sensitive alternating inversion recovery true-fast imaging and steady precession was performed to measure cortical and whole kidney perfusion.
RESULTS
T1 was higher in CKD within cortex and whole kidney, and there was association between T1 time and eGFR. No association was seen between kidney size and volume and either T1, or ASL perfusion. Perfusion was lower in CKD in cortex (136 ± 37 vs. 279 ± 69 ml/min/100 g; p < 0.001) and whole kidney (146 ± 24 vs. 221 ± 38 ml/min/100 g; p < 0.001). There was significant, negative, association between T1 longitudinal relaxation time and ASL perfusion in both the cortex (r = -0.75, p < 0.001) and whole kidney (r = -0.50, p < 0.001). There was correlation between eGFR and both cortical (r = 0.73, p < 0.01) and whole kidney (r = 0.69, p < 0.01) perfusion.
CONCLUSIONS
Significant differences in renal structure and function were demonstrated using ASL MRI. T1 may be representative of structural changes associated with CKD; however, further investigation is required into the pathological correlates of reduced ASL perfusion and increased T1 time in CKD
Pressure cycling technology for challenging proteomic sample processing: application to barnacle adhesive.
AbstractSuccessful proteomic characterization of biological material depends on the development of robust sample processing methods. The acorn barnacle Amphibalanus amphitrite is a biofouling model for adhesive processes, but the identification of causative proteins involved has been hindered by their insoluble nature. Although effective, existing sample processing methods are labor and time intensive, slowing progress in this field. Here, a more efficient sample processing method is described which exploits pressure cycling technology (PCT) in combination with protein solvents. PCT aids in protein extraction and digestion for proteomics analysis. Barnacle adhesive proteins can be extracted and digested in the same tube using PCT, minimizing sample loss, increasing throughput to 16 concurrently processed samples, and decreasing sample processing time to under 8 hours. PCT methods produced similar proteomes in comparison to previous methods. Two solvents which were ineffective at extracting proteins from the adhesive at ambient pressure (urea and methanol) produced more protein identifications under pressure than highly polar hexafluoroisopropanol, leading to the identification and description of >40 novel proteins at the interface. Some of these have homology to proteins with elastomeric properties or domains involved with protein-protein interactions, while many have no sequence similarity to proteins in publicly available databases, highlighting the unique adherent processes evolved by barnacles. The methods described here can not only be used to further characterize barnacle adhesive to combat fouling, but may also be applied to other recalcitrant biological samples, including aggregative or fibrillar protein matrices produced during disease, where a lack of efficient sample processing methods has impeded advancement. Data are available via ProteomeXchange with identifier PXD012730
High-Intensity Interval Training: A Potential Exercise Countermeasure During Human Spaceflight
High-intensity interval training (HIT) is an effective approach for improving a range of physiological markers associated with physical fitness. A considerable body of work has demonstrated substantial improvements in cardiorespiratory fitness following short-term training programmes, while emerging evidence suggests that HIT can positively impact aspects of neuromuscular fitness. Given the detrimental consequences of prolonged exposure to microgravity on both of these physiological systems, and the potential for HIT to impact multiple components of fitness simultaneously, HIT is an appealing exercise countermeasure during human spaceflight. As such, the primary aim of this mini review is to synthesize current terrestrial knowledge relating to the effectiveness of HIT for inducing improvements in cardiorespiratory and neuromuscular fitness. As exercise-induced fitness changes are typically influenced by the specific exercise protocol employed, we will consider the effect of manipulating programming variables, including exercise volume and intensity, when prescribing HIT. In addition, as the maintenance of HIT-induced fitness gains and the choice of exercise mode are important considerations for effective training prescription, these issues are also discussed. We conclude by evaluating the potential integration of HIT into future human spaceflight operations as a strategy to counteract the effects of microgravity
A large genome-wide association study of age-related macular degeneration highlights contributions of rare and common variants
Advanced age-related macular degeneration (AMD) is the leading cause of blindness in the elderly with limited therapeutic options. Here, we report on a study of \u3e12 million variants including 163,714 directly genotyped, most rare, protein-altering variant. Analyzing 16,144 patients and 17,832 controls, we identify 52 independently associated common and rare variants (P \u3c 5Ă10â8) distributed across 34 loci. While wet and dry AMD subtypes exhibit predominantly shared genetics, we identify the first signal specific to wet AMD, near MMP9 (difference-P = 4.1Ă10â10). Very rare coding variants (frequency \u3c 0.1%) in CFH, CFI, and TIMP3 suggest causal roles for these genes, as does a splice variant in SLC16A8. Our results support the hypothesis that rare coding variants can pinpoint causal genes within known genetic loci and illustrate that applying the approach systematically to detect new loci requires extremely large sample sizes
Centimeter to decimeter hollow concretions and voids in Gale Crater sediments, Mars
Voids and hollow spheroids between âŒ1 and 23 cm in diameter occur at several locations along the traverse of the Curiosity rover in Gale crater, Mars. These hollow spherical features are significantly different from anything observed in previous landed missions. The voids appear in dark-toned, rough-textured outcrops, most notably at Point Lake (sols 302-305) and Twin Cairns Island (sol 343). Point Lake displays both voids and cemented spheroids in close proximity; other locations show one or the other form. The spheroids have 1-4 mm thick walls and appear relatively dark-toned in all cases, some with a reddish hue. Only one hollow spheroid (Winnipesaukee, sol 653) was analyzed for composition, appearing mafic (Fe-rich), in contrast to the relatively felsic host rock. The interior surface of the spheroid appears to have a similar composition to the exterior with the possible exceptions of being more hydrated and slightly depleted in Fe and K. Origins of the spheroids as Martian tektites or volcanic bombs appear unlikely due to their hollow and relatively fragile nature and the absence of in-place clearly igneous rocks. A more likely explanation to both the voids and the hollow spheroids is reaction of reduced iron with oxidizing groundwater followed by some re-precipitation as cemented rind concretions at a chemical reaction front. Although some terrestrial concretion analogs are produced from a precursor siderite or pyrite, diagenetic minerals could also be direct precipitates for other terrestrial concretions. The Gale sediments differ from terrestrial sandstones in their high initial iron content, perhaps facilitating a higher occurrence of such diagenetic reactions
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