北票喇嘛洞三燕文化墓地人骨的牙病

本文对辽宁北标喇嘛洞三燕文化墓地出土人骨的牙病作了详细的观察。初步探讨了龋病和牙周病的罹患率与性别和年龄的关系,结果显示：（1）龋病的罹患率男女间差异不显著,而牙周病的罹患率性别差异显著。（2）龋病的罹患率与年龄变化具有一定关系,而牙周病的罹患率则与年龄变化关系密切。此外,对多生牙、先天缺额牙、融合牙、错位牙、第三臼齿的阻生情况也分别作了记录与分析。     

辽宁北票喇嘛洞遗址出土人骨稳定同位素分析

喇嘛洞遗址是我国北方地区一处以三燕文化墓葬为主的大型墓地,对其出土人骨进行C和N稳定同位素分析,可望了解先民的食谱,揭示其生活方式进而探索鲜卑与汉的相互联系。该遗址20个墓葬出土人骨的C、N含量以及C/N摩尔比反映了样品均保存较好,可用作食谱分析。人骨中骨胶原δ13C和δ15N分析显示,先民主要以C4类食物为食,且基本为素食,这当与发达的糜子和粟米农业密切相关,表明喇嘛洞遗址鲜卑生活方式已受到汉文化的强烈影响,由游猎为生转变为农业生产为主。对不同性别的先民食谱差异性进行t检验,发现男女食谱上不存在显著差异。样品BLM63和BLM99的δ15N值相对较高,揭示了其食物结构中含有一定量的肉类。     

北票喇嘛洞墓地魏晋十六国时期人骨的错(牙合)畸形

本文选择辽宁北票喇嘛洞墓地魏晋十六国时期人骨中牙列较完整的个体进行了错He畸形的调查。初步探讨了我国魏晋十六国时期古代居民中错He畸形的发病情况,结果显示：1)辽宁北票喇嘛洞墓地魏晋十六国时期人骨错He畸形的患病率为42．53％;在错He个体中,前牙拥挤所占比例最大,为56．76％;在Angle氏错He分类中,AngleⅠ类所占比例最大,为70．27％;2)错He畸形的患病率性别差异无统计学意义;3)人类经济类型所决定的饮食结构的改变与错He畸形的发病原因有关系。     

不同类型生态补偿在山水林田湖草生态保护与修复中的作用

生态补偿作为环境政策工具在环境保护和修复中发挥着重要作用,对山水林田湖草生态保护与修复也将起到支撑作用。通过梳理政府出资的生态补偿、市场化生态补偿以及政府和社会资本合作的生态补偿对山水林田湖草生态保护与修复的作用、实现的方式、适用的山水林田湖草生态保护与修复类型等,认为：政府出资的生态补偿,是山水林田湖草生态保护与修复的基础资金来源,尤其是针对在生态保护红线以内进行的生态保护与修复活动,市场主体无法通过生态保护与修复而实现营利,这时主要靠政府出资的生态补偿来实现生态保护与修复。市场化生态补偿是政府主导的生态补偿之外的重要手段,主要适用于能创造经济效益的生态保护与修复项目,它对于缓解财政支出压力,拓宽生态修复资金渠道和增加资本市场投资渠道都具有重要作用,是生态保护与修复融资的重要发展方向。政府与社会资本合作,可以充分发挥政府的统筹协调作用与市场的资源配置作用,各取所长,相互配合,共同致力于生态保护与修复。     

来自喀拉拉的报道

2001年7月的印度之行,我听到这样一个奇怪的事:在印度,动物学家们发现,新生的雄性大象没有象牙。没有人能解释这是为什么。只是有人说,这是大象为了保命。为了抵御人类,大象做为一个物种,今后还会有些什么变异,也没有人知道。 在印度,我还听科学家说到了这样两个数字:25年前,印度有64种大米,现在只剩下了4种;人们现在主要吃的蔬菜有17种左右,而森林里的植物有2000种之     

沙地也有忧伤

2002年7月,我带领着内蒙古农业大学的一小队学生到正蓝旗哈登胡硕夏营盘实习。那里是由国家“环北京地区防沙治沙科技支撑项目”的浑善达克沙地中的一个点,由我们学校会同正蓝旗林业局共同实施。 有道是“纸上得来终觉浅,绝知此事要躬亲”。这群孩子都是读水土保持与荒漠化防治专业的,平时在学校里专业课都学得不错,可一到大自然里都有一些傻眼了,怎么所学的知识和眼前看到的都好象不太一样,正可谓是理论和实际相     

基于生态系统服务视角的山水林田湖草生态保护与修复——以洞庭湖流域为例

山水林田湖草系统保护与修复的重要目标是维护和提升区域生态系统服务。基于山水林田湖草生命共同体理念,以维护和提升人类福祉所需的重要生态系统服务为目标,提出生态系统服务视角下的山水林田湖草系统治理框架,以实现流域生态系统整体保护、质量提升和格局优化。基于该框架,以洞庭湖流域为例,通过流域生态系统格局、生态系统质量状况分析、流域生态系统服务重要性评估和生态问题识别,构建流域生态安全格局,为实现可持续的山水林田湖草生命共同体提出系统保护与修复布局建议。通过洞庭湖流域的分析案例为流域山水林田湖草生态保护与修复重要区域的识别提供了可借鉴的指标和定量分析方法,为流域尺度构建生态安全格局、实现山水林田湖草系统保护和修复提供思路和途径。     

后疫情时代生态保护与可持续发展——中国生态文明与可持续发展2021年学术论坛述评

中国生态文明与可持续发展2021年学术论坛于2021年11月20日至21日在江西省南昌市举行,论坛共吸引1700余人次参与线上线下研讨。论坛的主题是“后疫情时代生态保护与可持续发展”。论坛围绕9个专题展开,分别是：(1)人地系统耦合与可持续发展;(2)国土空间规划与生态修复;(3)生态系统服务与生态产品价值实现;(4)农村宅基地退出与乡村发展;(5)山地水土保持与乡村振兴;(6)生态保护修复与可持续发展;(7)流域生态文明建设与高质量发展;(8)喀斯特区生态文明建设与可持续发展;(9)海洋生态文明建设与向海经济高质量发展。对我国生态保护与区域可持续发展研究的启示有：(1)将基于自然的解决方案纳入生态文明建设;(2)深化多源数据和多模型耦合支撑的可持续发展评估;(3)建立健全基于生态系统服务的生态产品价值核算体系。     

基于结构方程模型分析森林生态安全的影响因素

森林生态安全是维持国家生态安全的重要基础,也是人类生存的必要环境。森林不仅为人类提供木材和其他林副产品等实物价值,还具有美化环境、固碳释氧、涵养水源、防风固沙等生态服务价值,对维持生态平衡有重要作用。生态安全的相关研究多集中在构建评价指标评价森林生态安全,研究内容相对单一,而针对林业生态-产业共生关系的研究,并没有对林业产业类型进行区分,其次,林业产业发展对森林生态安全的影响研究较少。针对上述问题,在考虑产业分类的基础上,基于PSR理论和狭义的森林生态安全定义,利用31个省(市、自治区)3年的林业统计数据,运用PLS结构方程模型分析林业产业发展、森林生态保护对森林生态安全的影响及影响的大小,并分析了各地区森林生态保护的响应活动,为林业产业发展和森林生态保护的政策制定提供依据,从而促进林业的可持续发展。基于上述分析得出如下结果:(1)林业产业发展对森林生态安全无显著影响,但有部分子产业有森林生态安全有影响;(2)林业一产发展对森林生态安全有显著地直接影响,路径系数为0.175,间接影响不显著;(3)林业二产和三产发展对森林生态安全的直接影响和间接都不显著;(4)三类产业对林业产业发展的影响均显著,影响的大小分别为林业二产(0.636)、林业一产(0.204)、林业三产(0.151);(5)森林生态保护对森林生态安全有显著地直接影响,路径系数为0.619;(6)相对于其他地区,西部的森林生态保护活动积极性不高。由此得出如下结论:林业产业发展及林业二产、林业三产对森林生态安全未形成压力,只有林业一产发展对森林生态安全产生了正压力,需进一步加强林业产业结构的调整;加大保护响应力度对森林生态安全的影响大于合理利用的正压力;加强西部区域的森林生态保护力度,提高森林生态安全。     

由“发展骆驼，保护草原，加固中华民族的生态屏障”一文以及对其“某些观点值商榷”一文引发的一些思考

在 2 0 0 2年 9月间 ,通过电子邮件拜读了白图格吉扎布先生的文章“发展骆驼 ,保护草原 ,加固中华民族的生态屏障”(以下简称“骆驼”文 )。当时感到 ,作者大概对实际情况不太了解 ,文章中的有些概念不够清晰、准确 ,逻辑推理不够严谨 ,故仅将其作为学者间的个人交流对待。未曾想到此文最近在贵刊登出 ,并随之有了白永飞先生的“‘发展骆驼 ,保护草原 ,加固中华民族的生态屏障’一文中的某些观点值得商榷”的文章 (以下简称“商榷”文。两篇文章均见于《植物生态学报》2 0 0 2年第 6期 )。拜读了此两篇文章后 ,本人有言犹未尽的感觉 ,想加入…     

Prediction of gestational age by ultrasonic fetometry in llamas (Lama glama) and alpacas (Lama pacos)

Fetal biparietal diameter (BPD) and thorax height (TH) were measured by ultrasound during intrauterine growth in pregnant llamas (Lama glama) and alpacas (Lama pacos). The goal was to establish representative curves that allows estimation of gestational age (GA) from real-time ultrasonic measurements of these fetal structures at any stage of gestation. Llamas and alpacas were mated under controlled conditions. Ultrasound exams were conducted to determine pregnancy status 1 month later. Measurements of fetal BPD and TH were conducted from the second month of pregnancy until term. Observation and assessment of fetal TH was difficult during the last 3 months of pregnancy, specially in llamas. Regression curves were calculated from the data as a function of GA, with the best fit represented by the following equations: llama GA=(BPD-0.002399)43.02293,r=0.98,P<0.001; llama GA=(TH-0.07137)46.94485, r=0.95,P<0.001; alpaca GA=(BPD-0.11376)47.23287, r=0.98,P<0.001; alpaca GA=(TH-0.36436)52.87663, r=0.96,P<0.001, where GA was measured in days and BPD and TH in centimeters. Results indicate that ultrasonic measurement of these fetal biometric variables constitute a valuable tool to estimate GA at any stage of pregnancy in these domestic South American camelids.     

The structure of the gastric mucosa of the llamas (Lama guanocoe and Lama lamae). I. Forestomach]

The mucous membrane of the first and second compartments (ventral regions) as well as of the third compartment of Lama guanacoe and Lama lamae stomach shows tubular glands opening into pits. Below the surface epithelium blood capillaries of the fenestrated type form a regular network, each mesh of which surrounds a gastric pit. From a morphological point of view (thin section and freeze-fracture replicas) the columnar cells of the surface epithelium and those of the pits closest to the capillaries are largely similar to the epithelial cells of the rabbit gallbladder. This similarity suggests that at the level of the columnar cells sodium-dependent water reabsorption occurs. This reabsorption has already been demonstrated in the abovementioned compartments by physiological methods. The surface and foveolae epithelial cells as well as some cells of the tubular glands have a secretory function. Their secretory granules contain mucosubstances, as indicated by light-(PAS- and Alcian blue reactions) and electron microscopic (PA-TCH-Ag-reaction) histochemistry. The secretory granules originate from the Golgi complex which shows a positive histochemical reaction in its innermost sacculi at the electron microscope level. Endocrine cells (s. second part of this investigation) are rare. The mucosal membrane of each muscular lip separating the glandular sacs in the first compartment shows a stratified, not keratinized, squamous epithelium.     

Sweating in the guanaco (Lama guanicoe)

Sweat glands are present all over the skin, where sweat production varies from 4.98 to 73.36gm(-2)h(-1) of skin. Ambient temperatures between 20 and 33 degrees C are the main stimuli for activation of sweat glands, generating a heat loss ranging from 11.9 to 37% of standing basal metabolic rate. Respiratory water loss is not an important mechanism for heat dissipation. Water loss is controlled by postural changes in the guanaco.     

Superovulatory responses to eCG in llamas (Lama glama )

Llamas are copulation-induced single-ovulators, and multiple ovulation and embryo transfer (MOET) methods have not yet been developed for this species. Superovulatory responses to eCG given during an induced (Group A) or simulated (Group B) luteal phase were investigated using ultrasound to observe ovarian follicles and corpora lutea (CLs) and plasma progesterone was used to assess luteal function. Embryos were recovered nonsurgically. Group A (n = 19): donors were given 8 microg, im GnRH analogue (Day 0) to induce ovulation of a mature follicle, 1000 IU, im eCG (Day 7), and 250 microg PGF(2alpha) analogue (Day 9). Group B (n = 17): donors were given a subcutaneous progestagen implant (3 mg Norgestomet) at Days 0 to 7) and 1000 IU, im eCG (Day 5). When most (>65%) of the follicles in both Groups A and B had matured at 5 to 11 d post eCG, the donors were given 8 microg, im GnRH and mated once (n = 26) or twice within a 24-h interval (n = 10); embryos were recovered 6 to 9 d post ovulation. More follicles and corpora lutea were induced in Group B than in Group A, but a similar mean number of embryos were recovered (1.3 vs 1.6), and a similar proportion of donors yielded multiple embryos (35 vs 32%). The embryo recovery rate was similar for Groups A and B (39 and 37%), but it was higher (P < 0.001) with 2 (72%) rather than 1 (22%) mating, and it was negatively correlated with CL number (P < 0.05). Overall, 80% of the llamas had a precocious CL and elevated plasma progesterone concentrations when multiple follicles reached maturity. This was associated with increased subsequent superovulation and embryo recovery (P < 0.01). Peak plasma progesterone was positively correlated with the CL number (P < 0.05). From these results we conclude that superovulation may be achieved with eCG given during either an induced or a simulated luteal phase, that embryo recovery is improved following 2 matings rather than 1, and that MOET may indeed be feasible for use in the llama.     

Occurrence of microtubules during erythropoiesis in Llama, Lama glama

Studies on the ellipsoid erythroblasts of Llama, L a m gluma, L. during erythropoiesis showed the appearance of the marginal band composed of approximately 29 microtubules. As the maturation of erythrocytes goes on, the number of marginal band microtubules diminishes. No microtubules were found in mature erythrocytes of Llama.     

Melanins and melanosomes from llama (Lama glama L.)

Analysis of melanins and melanosomes in eight hair and skin samples taken of adult pigmented Argentine llamas (Lama glama L.) has been carried out. In each sample, eumelanins, pheomelanins and alkali-soluble melanins were identified. The total amount of melanins and the amount of eumelanins both decreased from black to reddish brown colour, while pheomelanins were found to be present in small quantities in each sample. Eumelanosomes were round and oval-shaped, displaying transverse striations clearly visible at low magnification. Dark brown samples revealed all four melanosomes stages. Stages I and II melanosomes appeared as large, asymmetrical vacuoles containing numerous microvesicles randomly scattered within an amorphous proteinaceous material (vesiculo-globular bodies). Stage III melanosomes had microgranular melanin deposits in the microvesicles and in the matrix. The fully melanized melanosomes (stage IV) were primarily round-shaped, showing an irregular outline and the electron-dense pigment was arranged to form large clusters. In light brown melanocytes, numerous melanosomes at different maturation stages could be found. Premelanosomes appeared ovoid, containing amorphous proteinaceous material and spotty and microgranular deposits. Mature melanosomes were fully melanized, homogeneously electron-dense, ovoid granules.     

Successful transfer of vitrified Ilama (Lama glama) embryos

The exploitation of the domestic animals species of South American camelids is of great social importance for the native people living in the High Andes. The reproductive physiology of these species is a unique challenge in the development of advanced breeding techniques. At present, the cryopreservation of embryos has not been developed and very few investigations have been conducted. The objective of the present work was to evaluate the in vivo survival of vitrified llama embryos after transfer to recipient females. Donors females were treated with a CIDR-estradiol benzoate-eCG regimen and were mated naturally 6 days after CIDR withdrawal. One ovulatory dose (8 microg) of GnRH was administered immediately after mating. A second mating was allowed 24 h later. Embryo recovery was performed nonsurgically between 8 and 8.5 days after the first mating. Twenty-two ova/embryos were recovered from 12 donor females. Hatched blastocysts were exposed to vitrification solution (20% glycerol + 20% ethylene glycol + 0.3 M sucrose + 0.375 M glucose + 3% polyethylene glycol (P/V)) in three steps, and after loading into 0.25 ml straws, were plunged into liquid nitrogen. For embryo transfer, recipients animals were ovulation-synchronized using GnRH administered at the same time as donors. A total of eight vitrified-warmed embryos and 12 fresh embryos were nonsurgically transferred to four and six recipient females, respectively (two embryo per recipient). The pregnancy rates were 50 and 33.3% for recipients that had received vitrified embryos and fresh embryos, respectively. The results demonstrated the effectiveness of this simple vitrification method for cryopreservation of llama embryos.     

Transvaginal collection and ultrastructure of llama (Lama glama) oocytes

Ultrasound-guided transvaginal follicle aspiration has been described as a noninvasive and repeatable procedure for oocyte collection in several species, but its use has not been described for any of the members of the family, Camelidae. A study was designed to determine the feasibility of an ultrasound-guided transvaginal approach for oocyte collection in llamas. Fifteen non-pregnant, adult female llamas (10 non-stimulated and 5 superstimulated) were examined by transrectal ultrasonography with a 7.5-MHz linear-array transducer to determine the number and diameter of follicles available for aspiration. After caudal epidural anesthesia was induced, the 7.5-MHz linear-array transducer was fastened to a long rigid handle and inserted intravaginally. The free hand was placed into the rectum to manipulate the ovaries, one at a time, in position against the vaginal wall over the face of the transducer. A 20-gauge, 55-cm-long, single-lumen needle was advanced through the vaginal fornix and into follicles > or = 3 mm in diameter. Follicular contents were aspirated using a regulated vacuum pump (flow rate = 33 mL/min; approximately 150 mm Hg) into a tube containing 3 mL of phosphate buffered saline and 0.2% BSA. Fluid was filtered (75 microm mesh), and oocytes were located and morphologically evaluated using a stereomicroscope. Overall, 134 follicles were aspirated, and 76 oocytes were collected (collection rate = 57%). Thirty-two oocytes (42%) were surrounded by multiple layers of compacted granulosa cells and had homogenous dark ooplasm; 13 oocytes (17%) were surrounded by the corona radiata layer only and had heavily granulated ooplasm; 9 oocytes (12%) were denuded and had homogenous dark ooplasm; and 22 oocytes (29%) were denuded and displayed signs of ooplasm degeneration. The ultrastructure of llama oocytes was similar to that of cattle except for conspicuous accumulation of large lipid droplets in the cytoplasm. Twenty-four hours after follicle aspiration, the ovaries were examined by transrectal ultrasonography and intrafollicular hematomas were detected in 3 llamas (9 of 48 follicles aspirated). Results demonstrate the potential utility of a transvaginal ultrasound-guided technique for oocyte collection and in vitro embryo production in llamas. Oocytes of llamas bear an ultrustructural resemblance to those of cattle, but are distinguished by a predominance of cytoplasmic lipid.