Estimation of wind erosion rates by using Cs-137 tracing technique: A case study in Tariat-Xilin Gol transect, Mongolian Plateau

Wind erosion is one of the major environmental problems in semi-arid and arid regions. Here we established the Tariat-Xilin Gol transect from northwest to southeast across the Mongolian Plateau, and selected seven sampling sites along the transect. We then estimated the soil wind erosion rates by using the Cs-137 tracing technique and examined their spatial dynamics. Our results showed that the Cs-137 inventories of sampling sites ranged from 265.63 +/- 44.91 to 1279.54 +/- 166.53 Bq.m(-2), and the wind erosion rates varied from 64.58 to 419.63 t.km(-2).a(-1) accordingly. In the Mongolia section of the transect (from Tariat to Sainshand), the wind erosion rate increased gradually with vegetation type and climatic regimes; the wind erosion process was controlled by physical factors such as annual precipitation and vegetation coverage, etc., and the impact of human activities was negligible. While in the China section of the transect (Inner Mongolia), the wind erosion rates of Xilin Hot and Zhengxiangbai Banner were thrice as much as those of Bayannur of Mongolia, although these three sites were all dominated by typical steppe. Besides the physical factors, higher population density and livestock carrying level should be responsible for the higher wind erosion rates in these two regions of Inner Mongolia.

NDVI spatial pattern and its differentiation on the Mongolian Plateau

GIMMS NDVI database and geo-statistics were used to depict the spatial distribution and temporal stability of NDVI on the Mongolian Plateau. The results demonstrated that: (1) Regions of interest with high NDVI indices were distributed primarily in forested mountainous regions of the east and the north, areas with low NDVI indices were primarily distributed in the Gobi desert regions of the west and the southwest, and areas with moderate NDVI values were mainly distributed in a middle steppe strap from northwest to southeast. (2) The maximum NDVI values maintained for the past 22 years showed little variation. The average NDVI variance coefficient for the 22-year period was 15.2%. (3) NDVI distribution and vegetation cover showed spatial autocorrelations on a global scale. NDVI patterns from the vegetation cover also demonstrated anisotropy; a higher positive spatial correlation was indicated in a NW-SE direction, which suggested that vegetation cover in a NW-SE direction maintained increased integrity, and vegetation assemblage was mainly distributed in the same specific direction. (4) The NDVI spatial distribution was mainly controlled by structural factors, 88.7% of the total spatial variation was influenced by structural and 11.3% by random factors. And the global autocorrelation distance was 1178 km, and the average vegetation patch length (NW-SE) to width (NE-SW) ratio was approximately 2.4:1.0.

Modeling the Effects of Habitat Fragmentation on the Movements of the Mongolian Gazelle in the Eastern Mongolian Steppe

The Mongolian gazelle, Procapra gutturosa, resides in the immense and dynamic ecosystem of the Eastern Mongolian Steppe. The Mongolian Steppe ecosystem dynamics, including vegetation availability, change rapidly and dramatically due to unpredictable precipitation patterns. The Mongolian gazelle has adapted to this unpredictable vegetation availability by making long range nomadic movements. However, predicting these movements is challenging and requires a complex model. An accurate model of gazelle movements is needed, as rampant habitat fragmentation due to human development projects - which inhibit gazelles from obtaining essential resources - increasingly threaten this nomadic species. We created a novel model using an Individual-based Neural Network Genetic Algorithm (ING) to predict how habitat fragmentation affects animal movement, using the Mongolian Steppe as a model ecosystem. We used Global Positioning System (GPS) collar data from real gazelles to “train” our model to emulate characteristic patterns of Mongolian gazelle movement behavior. These patterns are: preferred vegetation resources (NDVI), displacement over certain time lags, and proximity to human areas. With this trained model, we then explored how potential scenarios of habitat fragmentation may affect gazelle movement. This model can be used to predict how fragmentation of the Mongolian Steppe may affect the Mongolian gazelle. In addition, this model is novel in that it can be applied to other ecological scenarios, since we designed it in modules that are easily interchanged.

Bacterial biofilms in cholesteatomas of Mongolian gerbils

This paper studies cholesteatomas of Mongolian gerbils and the presence of bacterial biofilms.

Ultrastructural analysis of the low level laser therapy effects on the lesioned anterior tibial muscle in the Gerbil

Low level laser therapy (LLLT) is known for its positive results but studies on the biological and biomodulator characteristics of the effects produced in the skeletal muscle are Still lacking. In this Study the effects of two laser dosages, 5 or 10 J/cm(2), on the lesioned tibial muscle were compared. Gerbils previously lesioned by 100 g load impact were divided into three groups: GI (n = 5) controls, lesion non-irradiated; GII (n = 5), lesion irradiated with 5 J/Cm(2) and GIII (n = 5), lesion irradiated with 10 J/cm(2), and treated for 7 consecutive days with a laser He-Ne (lambda = 633 rim). After intracardiac perfusion, the muscles were dissected and reduced to small fragments, post-fixed in 1% osmium tetroxide, dehydrated in increasing alcohol concentrations, treated with propylene oxide and embedded in Spurr resin at 60 degrees C. Ultrafine Cuts examined on a transmission electron microscope (Jeol 1010) revealed in the control GI group a large number of altered Muscle fibers with degenerating mitochondria, intercellular substance containing degenerating cell fragments and budding blood capillaries with Underdeveloped endothelial cells. However, groups GII and GIII showed muscle fibers with few altered myofibrils, regularly contoured mitochondria, ample intermembrane spaces and dilated mitochondrial crests. The clean intercellular Substance showed numerous collagen fibers and capillaries with multiple abluminal processes, intraluminal protrusions and several pinocytic vesicles in endothelial cells. it was concluded that laser dosages of 5 or 10 J/cm(2) delivered by laser He-Ne (lambda = 633 rim) during 7 consecutive days increase mitochondrial activity in muscular fibers, activate fibroblasts and macrophages and stimulate angiogenesis, thus suggesting effectivity of laser therapy tinder these experimental conditions. (C) 2009 Elsevier Ltd. All rights reserved.

Tissue evidence of the testosterone role on the abnormal growth and aging effects reversion in the gerbil (Meriones unguiculatus) prostate

Prostate differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Abundant biological data suggest that androgens play an important role in the development of the prostate cancer and other prostatic diseases. The objective of this work was to evaluate the effects of the testosterone supplementation in gerbil (a new experimental model) at different ages. Tissues from experimental animals were studied by histological and histochemistry procedures, androgen receptor immunohistochemistry assay, morphometric-stereological analysis, and transmission electron microscopy (TEM). After the treatment were observed increase of prostate weight and epithelium height in all ages studied. In some adult and aged treated animals, hyperplasic and displasic process were observed, including prostatic intraepithelial neoplasias and adenocarcinomas. Increase of the thickness of the smooth muscle cell (SMC) layer was observed in pubescent and adult animals and TEM revealed apparent SMC hypertrophy. An apparent increase in the frequency of blood vessels distributed by the subepithelial stroma in the treated animals was noticed. Reversion of the natural effects of aging on the prostate was observed in the aged treated animals in some acini of the gland. These data demonstrate that the gerbil prostate is susceptible to androgenic action at the studied ages and it can serve, for example, as experimental model to studies of prostate neoplasic process induction and hormonal therapy in aged animals.

Structure, histochemistry, and ultrastructure of the epithelium and stroma in the gerbil (Meriones unguiculatus) female prostate

The female prostate has aroused scientific interest because it is subjected to the same diseases compromising the male prostate during aging. The objective of this work was to characterize structurally, cytochemically, and ultrastructurally the tissue compartments of the normal adult female prostate of Meriones unguiculatus gerbils. The morphological analyses showed that the gerbil's female prostate is constituted of a cluster of glands and ducts inserted in a musculofibrous stroma. The alveolar epithelium is differentiated and consisted of basal proliferating cells, intermediary cells, and secretory cells. The secretory cells are the most numerous cell type and continuously secrete glycoproteins. The basal cells are the source of the secretory cells and they are then responsible for the alveolus renovation. The prostatic stroma is abundant and rich in elastic and collagen fibers, which are closely associated with smooth muscle cells and fibroblasts. The results showed that the gerbil's female prostate shows morphological and ultrastructural homology to the human female prostate (Skene's gland), and despite being a small organ, it is a mature and physiologically active gland. (C) 2003 Elsevier Ltd. All rights reserved.

Biological behavior of the gerbil ventral prostate in three phases of postnatal development

In this study, we characterized the gerbil's ventral prostate histology ultrastructurally and quantitatively throughout three phases of postnatal development (young, adult, and old) in order to comprehend its biological behavior and propensity to developing spontaneous lesions with aging. The gerbil prostate is composed of alveoli and ducts immersed in a stroma composed of smooth muscle, fibroblasts, collagen and elastic fibers and vessels. The prostate tissue components present morphological and quantitative aspects that vary according to age. Young animals have an immature gland with modest secretory activity. Synthetic activity remained stable in adult and old gerbil. However, prostatic morphology was altered in the aging, showing an increased epithelium and stromal fibrosis. The nuclei of the secretory cells increased with aging, whereas nucleoli presented few alterations during postnatal development. The epithelial proliferation and stromal remodeling noted in this study indicate that the gerbil prostate may respond to the androgen declines typical of senescence through epithelial proliferation and stromal remodeling.

Acid phosphatase activity in gerbil prostate: comparative study in male and female during postnatal development

The prostate is present in both male and female mammals. It is composed of secretory epithelium, connective stroma, smooth muscle and neuroendocrine cells, which are under hormonal regulation. Acid phosphatases catalyze the hydrolysis of orthophosphate monoesters. We have compared the expression of acid phosphatases in gerbil (Meriones unguiculatus) prostate glands in both sexes using young, adult and old animals. Eighteen prostates were isolated, frozen, sectioned, fixed, incubated with sodium beta-glycerophosphate sodium, washed with acetate buffer solution, treated with ammonium sulfide and counterstained with Methyl-Green aqueous solution. Ultracytochemical analyses were also conducted. This substrate revealed total acid phosphatase activity. The expression of the enzyme was heterogeneous, occurring in all ages during postnatal development. The data. revealed that the female prostate matured before the male prostate. In addition, acid phosphatase activity in both sexes was regulated by androgen variation concomitant with development. (C) 2004 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.