Regulation of erythrocyte cation and water content in sickle cell anemia

The pathophysiological events in sickle cell disease are critically dependent on the intracellular concentration of hemoglobin S, which varies inversely with cell cation and water content. Erythrocytes of SS homozygotes exposed to oxygen or carbon monoxide decrease their potassium and water content through a pathway for potassium transport that is activated by both cell swelling and decrease in internal pH. This pathway is not inhibited by ouabain either with or without bumetanide. When SS erythrocytes were separated according to density, the pH- and volume-dependent potassium transport was greatest in the least dense fraction and was reduced in the densest cells. This pathway, which does not depend on polymerization of sickle hemoglobin, may be important in regulating the cation and water content of SS erythrocytes.     

GONG Observations of Solar Surface Flows

Doppler velocity observations obtained by the Global Oscillation Network Group (GONG) instruments directly measure the nearly steady flows in the solar photosphere. The sun's differential rotation is accurately determined from single observations. The rotation profile with respect to latitude agrees well with previous measures, but it also shows a slight north-south asymmetry. Rotation profiles averaged over 27-day rotations of the sun reveal the torsional oscillation signal-weak, jetlike features, with amplitudes of 5 meters per second, that are associated with the sunspot latitude activity belts. A meridional circulation with a poleward flow of about 20 meters per second is also evident. Several characteristics of the surface flows suggest the presence of large convection cells.     

Neurological diseases of ruminant livestock in Australia. II: toxic disorders and nutritional deficiencies

The second in this series of clinical reviews on neurological diseases in ruminant livestock in Australia examines toxic disorders associated with plant and microbial toxins as well as the neurological effects of vitamin and mineral deficiencies. The aim of these reviews is to assist in the surveillance of neurological diseases, especially the transmissible spongiform encephalopathies.     

兰州市尘暴过程中降尘粒度特征探析

通过对兰州市两次强度上有较大差异的尘暴样的采集、粒度分析及其与自然降尘样的对比研究,揭示出兰州市尘暴降尘粒度特性的一些细微特征。不论是自然降尘样还是尘暴样,皆以4～63μm的粉砂为主,说明粉砂粒级的颗粒是兰州地区自然降尘与沙尘暴所携带的主要组分;虽然含量甚微,但是尘暴样中存在近源低空气流所搬运的粒径(181.97～724.44μm)较大的粗颗粒物质。在粒径-体积百分含量曲线上,尘暴样基本上为三峰分布模式,区别于自然降尘样的双峰模式。同时,尘暴样具有向粗、细颗粒区间(尤其是细颗粒区间)延伸并富集的特点,尘暴强度越大,其延伸富集的程度也越明显,而且,随着尘暴强度的增大,其主峰的众数粒径呈减小趋势。     

Reservoir to river: Quantifying fine-scale fish movements after translocation

Translocation of individuals is a widely used tool in the conservation of threatened species. The movement behaviours of translocated individuals in their new environment are a key factor that can influence translocation success (i.e. survival and reproduction). In this study, eel-tailed catfish (Tandanus tandanus) and Murray cod (Maccullochella peelii) movements were monitored using fine-scale acoustic telemetry over a 5-month period in two lowland rivers in eastern Australia. Fine-scale movement and habitat selection were compared among translocated lacustrine and resident riverine T. tandanus and between species. We found no difference in fine-scale movement behaviours between translocated and resident T. tandanus; however, there was some variation in movement response to environmental variation between species. In contrast, habitat selection varied not only between the two species, but also between resident and translocated T. tandanus individuals. Notably, activity was significantly lower in the first day after release compared to the remainder of the study period. Although T. tandanus translocated from a reservoir had never experienced the environmental fluctuations of a riverine system, individuals still responded in the same way as resident riverine fish, suggesting an innate behavioural response. However, this was not the case for habitat selection, where translocated individuals preferred habitats more common in their source population's lacustrine environment. The findings of this study are important in guiding future conservation efforts involving the translocation of wild-caught fish, primarily the importance of the suitable habitat at the release site to ensure the success and persistence of translocated populations.     

Urinary catheterisation of female dogs: a comparison between three techniques for catheter placement

The objective of this study was to describe a new technique for urinary catheterisation of female dogs using a novel catheterisation device (NCD) and to compare the time taken to place a catheter using this technique with traditional techniques. A secondary objective was to survey participants on which of the techniques they preferred. Female canine cadavers of varying sizes were utilised and veterinary students who had not previously placed a urinary catheter were enrolled. Each participant performed three catheterisation techniques, Visual with speculum (SPEC), Blind Palpation (BP) and catheterisation with NCD on three sizes of dog. Time required using each technique was compared using Kaplan–Meier plots and mixed models Cox Proportional Hazards regression. Median times to catheterisation were 300 s (IQR 261–417 s) with the SPEC method, 420 s (IQR 253–545 s) with the NCD method and 725 s (574–1032s) with the BP method. Both SPEC and NCD methods were significantly faster compared to the BP method, with Hazard Ratios of 3.66 (95% CI 1.94–6.91, P < 0.001) and 3.57 (95% CI 1.87–6.81, P < 0.001), respectively. Six of nine participants found the NCD the easiest technique, 5/9 of the participants found the palpation technique most difficult and 4/9 found the speculum technique most difficult. BP appears to be the technique of least preference and increased time requirement. The novel urinary catheterisation device may provide a simpler method of visualisation of the urethral papilla and may provide a more sterile way of placing the catheter, although further investigation is needed to confirm this.