Designing fecal pellet surveys for snowshoe hares

Index methods can be valuable for monitoring forest-dwelling vertebrates over broad spatial or temporal scales. Fecal pellet counts are often used as an index of density or habitat use of snowshoe hares, Lepus americanus, but previous surveys have used different plot types and sample sizes, leading to problems comparing results from different studies and questions about the inferential power of each study. In this paper, we use field data and simulations to examine how the precision, bias, and efficiency of four commonly used plot types vary with plot type, pellet density, and sample size. Although no one plot type was consistently superior, we recommend thin rectangles (5.08 cm × 305 cm (2 in. × 10 ft), 0.155 m²) or 1 m² circles over 0.155 m² circles or 10 cm × 10 m (1 m²) rectangles. We recommend that researchers explicitly address the power of their survey design to detect different pellet densities, because much larger sample sizes are needed at low pellet densities than at high pellet densities to obtain similar precision. Small sample sizes are also much more likely to be biased, which could lead to incorrect inferences about management of snowshoe hare populations. Both uncleared and cleared plots performed well and will have value in different research contexts.     

Carbon allocation and morphology of cherrybark oak seedlings and sprouts under three light regimes

• ? Continued problems in regenerating oak forests has led to a need for more basic information on oak seedling biology.
• ? In the present study, carbon allocation and morphology were compared between cherrybark oak (Quercus pagoda Raf.) seedlings and sprouts at 1-Lag grown in full, 47%, and 20% sunlight.
• ? Results indicated that cherrybark oak seedling carbon allocation and morphology responded plastically to light availability. In full light, roots were sinks for ¹⁴C, while shoots were sinks for ¹⁴C under reduced light availability. Cherrybark oak sprouts exhibited similar carbon allocation patterns in response to light availability, but displayed stronger shoot sinks than seedlings when grown underreduced light availability. We also showed that young oak sprout roots are a sink for ¹⁴C-photosynthates.
• ? Results from this study point to the need for a morphological index for oak sprout development so more precise comparisons in sprout development and physiology can be made with seedlings.

     

The relationships among palpator experience, milk progesterone concentration and estrus and fertility in cows with palpable corpora lutea treated with cloprostenol

Two hundred and fifty-one cows fresh at least 37 days with normal reproductive tracts and palpable ovarian structures which clinicians believed to be corpora lutea and which were presumed to be producing progesterone were treated with 500 micrograms of cloprostenol. The cows were stratified into three groups based on milk progesterone concentrations in whole milk samples taken at the time of examination. The low group had milk progesterone concentrations less than or equal to 1 ng/ml, the intermediate group had milk progesterone concentrations between 1 and 3 ng/ml, and the high group had milk progesterone concentrations greater than or equal to 3 ng/ml. The proportion of cows in each group inseminated within 5 days of treatment and the fertility at that breeding were compared. There were no significant differences among the groups with respect to the proportion of cows that came into estrus within 5 days. However, the conception rate of the high group (54%) was significantly greater than that of the intermediate group (26%). To study the relationship between practitioner experience and diagnostic accuracy the proportion of cows with low, intermediate and high concentrations of progesterone selected by clinicians with more than 3 years experience was compared to that for clinicians with 3 years of experience or less. Less experienced clinicians were significantly more likely to make a false positive diagnosis of functional luteal tissue in cows with palpable ovarian structures than were more experienced clinicians.     

不同转基因番茄GalUR的表达与Vc含量

为了得到高维生素C（Vc）含量新品种,克隆和构建了GalUR半乳糖醛酸还原酶基因,并转入了番茄.通过不同转基因突变体GalUR基因表达和Vc含量分析发现：GalUR基因在转GalUR基因番茄中得到了过量表达;在转FRO2-铁还原酶基因的番茄突变体中表达量增加了60%;在耐贮藏转基因番茄F3、F2、F1中也均高于对照,其中F3的表达量最高,是对照的2～3倍;在非转基因中蔬4号和6号的表达量高于丽春番茄1倍;所有供试GalUR基因表达量均为红果最多、粉红果次之,青果最少.转基因番茄果实Vc含量变化与上述GalUR基因的表达有相同规律.转GalUR3基因番茄果实和叶片Vc含量高于对照2倍以上.GalUR基因的表达还与乙烯合成酶基因ACS、CTR1和铁还原酶FRO2基因的表达有关.     

The Interdependence of Deformational and Thermal Processes in Mountain Belts

Crustal temperatures within collisional orogens are anomalously high compared with temperatures at comparable depths in stable continents, which is evidence of thermal processes that are fundamental to orogenesis. These temperatures can be explained by the redistribution of crust enriched in heat-producing elements through the accretion of crust from the down-going plate to the upper plate and surface erosion. With the use of geologically reasonable rates, the model results predict high temperatures (over 600°C) and inverted upper-plate geotherms (about 100°C over 20 kilometers) at shallow depths (20 to 40 kilometers) by 25 to 35 million years after collision. This study emphasizes the interdependence of deformational, surficial, and thermal processes.     

Laser 40Ar/39Ar Evaluation of Slow Cooling and Episodic Loss of 40Ar from a Sample of Polymetamorphic Muscovite

Volume diffusion models predict that crystals with large diffusion dimensions can record a wide range of thermal conditions in the Earth's crust. Direct measurements of the zoning of radiogenic argon-40 in single muscovite porphyroblasts, from a complex terrain in the Vermont Appalachians, record multiple crustal events that span 150 million years. The crystal radius was the effective dimension for argon diffusion (approximately 1000 micrometers). Late deformation features inside the crystals locally decreased the diffusion dimension and promoted loss of argon-40. Zoning patterns of radiogenic isotopes, as observed in this study, are an increasingly important diagnostic tool for studying the thermal record of tectonic processes.     

Transitions between blocked and zonal flows in a rotating annulus with topography

The mid-latitude atmosphere is dominated by westerly, nearly zonal flow. Occasionally, this flow is deflected poleward by blocking anticyclones that persist for 10 days or longer. Experiments in a rotating annulus used radial pumping to generate a zonal jet under the action of the Coriolis force. In the presence of two symmetric ridges at the bottom of the annulus, the resulting flows were nearly zonal at high forcing or blocked at low forcing. Intermittent switching between blocked and zonal patterns occurs because of the jet's interaction with the topography. These results shed further light on previous atmospheric observations and numerical simulations.