Experimental infection with equine herpesvirus type 1 (EHV-1) induces chorioretinal lesions

Equine herpesvirus myeloencephalitis (EHM) remains one of the most devastating manifestations of equine herpesvirus type 1 (EHV-1) infection but our understanding of its pathogenesis remains rudimentary, partly because of a lack of adequate experimental models. EHV-1 infection of the ocular vasculature may offer an alternative model as EHV-1-induced chorioretinopathy appears to occur in a significant number of horses, and the pathogenesis of EHM and ocular EHV-1 may be similar. To investigate the potential of ocular EHV-1 as a model for EHM, and to determine the frequency of ocular EHV-1, our goal was to study: (1) Dissemination of virus following acute infection, (2) Development and frequency of ocular lesions following infection, and (3) Utility of a GFP-expressing virus for localization of the virus in vivo. Viral antigen could be detected following acute infection in ocular tissues and the central nervous system (experiment 1). Furthermore, EHV-1 infection resulted in multifocal choroidal lesions in 90% (experiment 2) and 50% (experiment 3) of experimentally infected horses, however ocular lesions did not appear in vivo until between 3 weeks and 3 months post-infection. Taken together, the timing of the appearance of lesions and their ophthalmoscopic features suggest that their pathogenesis may involve ischemic injury to the chorioretina following viremic delivery of virus to the eye, mirroring the vascular events that result in EHM. In summary, we show that the frequency of ocular EHV-1 is 50-90% following experimental infection making this model attractive for testing future vaccines or therapeutics in an immunologically relevant age group.     

The importance of in situ site loss in nature reserve selection: Balancing notions of complementarity and robustness

Because the threat of habitat destruction can never be entirely eliminated, there is a legitimate concern that some reserve networks, especially highly complementary ones with minimal species overlap, may be predisposed to severe losses in species representation if one or more core reserve sites are destroyed. In order to address this problem in a systematic way, we propose the use of two different optimization models for designing complementary reserve networks that are also highly robust to possible site losses. Given limited budgets, the first maximizes expected species representation over all possible site loss patterns while the second maximizes a combination of representation given all sites and remaining representation following the worst-case loss of a restricted subset of reserve sites. By incorporating reserve loss in fundamentally different ways, these two models provide a range of options in terms of information requirements, assumptions about risk aversion, and structural complexity. We compare both of these methods to a more standard approach, which completely ignores the inherent risk posed by reserve site loss. Results confirm that significantly more robust solutions can be obtained for a marginal decrease in initial species representation within the reserve system.     

The physiological and biochemical response of standardbred horses to exercise of varying speed and duration

LINDHOLM, ARNE and BENGT SALTIN: The physiological and biochemical response of standardbred horses to exercise of varying speed and duration. Acta vet. scand. 1974, 15, 310–324. — Welltrained standardbred horses were studied to examine the metabolic response to excercise of various speeds and duration. Comparisons between interval (400, 700, 1,000 and 2,000 m) and continuous trotting (1 hr., 2 hrs.) and racing were made.Muscle and rectal temperatures were recorded before and immediately after each work bout. Heart rate was linearly related to trotting speed, and maximal heart rate (240 beats × min.⁻¹) was achieved when trotting at least 700 m at close to maximal speed (12.0–12.5 m×sec.⁻¹).Biopsy specimens from the gluteus medius muscle and venous blood were obtained before and after each work bout.Muscle and blood lactate values were markedly increased first at speeds close to maximal speed (11.4–12.5 m×sec.⁻¹). Trotting 6×700 m at 12.5 m×sec.⁻¹ produced as high muscle and blood lactate values as 23.7 and 19.0 mmol×kg⁻¹ wet weight and l⁻¹, respectively. Corresponding values after a race were about 15 mmol×kg⁻¹ (muscle) and l⁻¹ (blood).Glycogen utilization was related to work intensity and was most pronounced during the first work bouts. At a speed of 12 m×sec.⁻¹ and trotting 2000 m, there was a glycogen utilization of near 12 mmol glucose units × kg⁻¹ × min.⁻¹ wet muscle.It is concluded that interval training over a distance of 700–1000 m repeated 4–6 times with a trotting speed close to maximal speed (11.4–12.5 m×sec.⁻¹) appears to be optimal.ATP; CP; blood lactate; glycogen utilization; heart rate; horse skeletal muscle; muscle lactate; racing training.     

美国大豆工业海洋网箱水产养殖技术近海海水鱼类养殖网箱工程技术手册（二十四）

8．总结此报告对OCAT网箱刚性框架设计的结构完整性作了分析研究。二种环境负载方案的结果被用作输入值：2．0米／秒的水流速度和风暴波浪级别时1．5米／秒的水流速度。整个网箱框架首先通过二组负载方案用梁柱的分析方法进行分析。这些负载方案包括在海洋环境状态下在网箱框架上的应力。还使用了HDPE弹性模数的保守值。第二次的分析研究了多数负载状态下时框架的稳定性。     

Use of modeled photosynthesis and decomposition to describe tree growth at the northern tree line

Growth of subarctic Scots pine (Pinus sylvestris L.) trees was investigated by a combination of process-based models and dendroecological approaches. Tree ring width indices were strongly autocorrelated and correlated with simulated photosynthetic production of the previous year and with organic matter N mineralization of the current year. An autoregressive model, with photosynthesis and N mineralization as external inputs, explained growth of the trees well. However, relationships for the period 1950-1992 differed significantly from relationships for the period 1876-1949; the slope of the regression of tree ring width index and photosynthesis was lower for the 1950-1992 period. Also, the autocorrelation structure of the data changed. First-order autocorrelation decreased and second-order autocorrelation increased from the earlier to the later period. This means that growth is becoming less sensitive to variations in photosynthetic production, whereas the relationships between growth and N mineralization are remaining fairly constant. We postulate that, although photosynthesis has increased in response to increasing CO2 concentrations, tree growth rate cannot parallel the increase in photosynthesis because potential growth rate is limited directly by temperature.     

Conformational control of the Ste5 scaffold protein insulates against MAP kinase misactivation

Cells reuse signaling proteins in multiple pathways, raising the potential for improper cross talk. Scaffold proteins are thought to insulate against such miscommunication by sequestering proteins into distinct physical complexes. We show that the scaffold protein Ste5, which organizes the yeast mating mitogen-activated protein kinase (MAPK) pathway, does not use sequestration to prevent misactivation of the mating response. Instead, Ste5 appears to use a conformation mechanism: Under basal conditions, an intramolecular interaction of the pleckstrin homology (PH) domain with the von Willebrand type A (VWA) domain blocks the ability to coactivate the mating-specific MAPK Fus3. Pheromone-induced membrane binding of Ste5 triggers release of this autoinhibition. Thus, in addition to serving as a conduit guiding kinase communication, Ste5 directly receives input information to decide if and when signal can be transmitted to mating output.     

Comment on "Global resilience of tropical forest and savanna to critical transitions"

Hirota et al. (Reports, 14 October 2011, p. 232) used spatial data to show that grasslands, savannas, and forests represent opposing stable states. Reanalyzing their data and drawing from temporal studies, we argue that spatial analyses underestimate the bistability of grasslands and savannas due to limitations of substituting space for time. We propose that temporal and spatial data are needed to predict critical transitions between grasslands and savannas.     

Rabies surveillance in the United States during 2011

Summary-During 2011, 49 states and Puerto Rico reported 6,031 rabid animals and 6 human rabies cases to the CDC, representing a 1.9% decrease from the 6,153 rabid animals and 2 human cases reported in 2010. Approximately 92% of reported rabid animals were wildlife. Relative contributions by the major animal groups were as follows: 1,981 raccoons (32.8%), 1,627 skunks (27.0%), 1,380 bats (22.9%), 427 foxes (7.1%), 303 cats (5.0%), 65 cattle (1.1%), and 70 dogs (1.2%). Compared with 2010, there was a substantial increase in the number of rabid skunks reported. Six cases of rabies involving humans were reported from California, Massachusetts, New Jersey, New York, and South Carolina. Three cases reported from Massachusetts, New Jersey, and New York were determined to be a result of canine rabies virus variants acquired outside the United States.