ANIMAL VOCABULARIES     

Palmer CB 《Science (New York, N.Y.)》1893,22(549):80-81

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FLORIDA. PITCHER PLANT     

Palmer CB 《Science (New York, N.Y.)》1892,20(503):171-172

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Determinants of native avian richness in suburban remnant vegetation: Implications for conservation planning     

Grant C. Palmer  James A. Fitzsimons  Mark J. Antos  John G. White 《Biological conservation》2008,141(9):2329-2341

While urban areas are increasingly recognized as having potential value for biodiversity conservation, the relationship between biodiversity and the structure and configuration of the urban landscape is poorly understood. In this study we surveyed birds in 39 remnant patches of native vegetation of various sizes (range 1-107 ha) embedded in the suburban matrix in Melbourne, Australia. The total richness of species within remnants was strongly associated with the size of remnants. Remnant-reliant species displayed a much stronger response to remnant area than matrix-tolerant species indicating the importance of large remnants in maintaining representative bird assemblages. Large remnants are important for other ecological groups of species including migratory species, ground foraging birds and canopy foraging birds. Other landscape (e.g. amount of riparian vegetation) and structural components (e.g. shrub cover) of remnants have a lesser role in determining the richness of individual remnants. This research provides conservation managers and planners with a hierarchical process to reserve design and management in order to conserve the highest richness of native species within urban areas. First of all, conservation efforts should preferentially focus on the retention of larger remnants of native vegetation. Second, where possible, riparian vegetation should be included within reserves or, where it is already present, should be carefully managed to ensure its integrity. Third, efforts should be focused at maintaining appropriate habitat and vegetation structure and complexity.  相似文献   

Foliar washoff potential and simulated surface runoff losses of trifloxysulfuron in cotton     

Matocha MA  Krutz LJ  Reddy KN  Senseman SA  Locke MA  Steinriede RW  Palmer EW 《Journal of agricultural and food chemistry》2006,54(15):5498-5502

The surface runoff potential of trifloxysulfuron {N-[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluoroethoy)-pyridin-2-sulfonamide sodium salt} in cotton (Gossypium hirsutum L.) production systems has not been evaluated. The objectives of this study were to (i) determine sorption/desorption coefficients for trifloxysulfuron; (ii) quantify foliar washoff of trifloxysulfuron when applied to cotton at the five-leaf stage; and (iii) determine the surface runoff potential of trifloxysulfuron when applied to cotton at the five-leaf stage and to bare soil. Freundlich sorption and desorption coefficients were 1.15 and 1.22, respectively. Sorption data indicated that trifloxysulfuron was moderately sorbed to soil and that it will be transported primarily in the dissolved phase of surface runoff. Foliar washoff studies revealed that approximately 91% of trifloxysulfuron applied to cotton at the five-leaf stage was available for washoff 72 h after application. Simulated rainfall (7.5 cm h-1) applied 1 day after herbicide application (7.9 g ha-1) resulted in average concentrations of trifloxysulfuron in surface runoff water of 0.8 microg L-1 for bare plots and 1.3 microg L-1 for cotton plots. Cumulative trifloxysulfuron losses in surface runoff from bare plots and cotton plots were 0.13 and 0.21 g ha-1, respectively. These values correspond to fractional losses of 1.7% for bare plots and 2.7% for cotton plots. Greater runoff losses of trifloxysulfuron from cotton plots were attributed to foliar washoff. Trifloxysulfuron runoff losses may be curtailed if the herbicide is applied early postemergence when canopy coverage is minimal, thereby reducing the potential for foliar washoff.  相似文献   

Ultrastructural,Sensory and Functional Anatomy of the Northern Elephant Seal (Mirounga angustirostris) Facial Vibrissae          下载免费PDF全文

H. Smodlaka  I. Galex  L. Palmer  J. A. Borovac  W. A. Khamas 《Anatomia, histologia, embryologia》2017,46(5):487-496

Vibrissae (whiskers) play a key role in underwater orientation in foraging phocids through vibrotactile sensation processing. Our aim was to evaluate the structure of northern elephant seal (NES) vibrissae by means of light (LM) and transmission electron microscopy (TEM), in order to elucidate their function. Vibrissal follicles were processed using standardized laboratory methods and LM/TEM techniques. Individual follicular axonal numbers were counted and axonal diameter measured and averaged. NES have mystacial, rhinal, supraorbital and labial vibrissae. The vibrissal follicles are histologically subdivided into a ring, upper and lower cavernous sinuses (LCS). Each vibrissa is innervated by the deep vibrissal nerve. The average number of axons per large mystacial vibrissa is 1804 (±123), rhinal 985 (±241), supraorbital 1,064 (±204) and 374 (±65) in labial vibrissa. The entire vibrissal system carries an estimated 148 573 axons, and mystacial vibrissae alone have 125 323 axons. Axonal conduction velocity for each vibrissal type is 55.26 m/s for labial, 56.58 m/s for rhinal and 35.88 m/s for mystacial vibrissae. TEM and LM revealed a plethora of mechanoreceptors within the vibrissal follicles: Merkel cell‐neurite complexes, lanceolate and pilo‐Ruffini end organs. A vast number of sensory axons projecting from the entire vibrissal system indicate that the vibrissal sensory area takes up a large proportion of phocids’ somatosensory cortex. In conclusion, NES has highly sensitive and finely tuned vibrotactile vibrissal sense organs.  相似文献   

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders          下载免费PDF全文

NLAF Sarmento  EFF Martins  DC Costa  WS Silva  CC Mattioli  MR Luz  RK Luz 《Reproduction in domestic animals》2017,52(1):144-152

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.  相似文献   

Effects of Forest Clearance and Cultivation on Bulk Density Variations and Relationships with Texture and Organic Matter in Tephra Soils of Mount Kupe (Cameroon)     

Roger Kogge Enang  Bernard Palmer Kfuban Yerima  Georges Kogge Kome  Eric Van Ranst 《Communications in Soil Science and Plant Analysis》2017,48(19):2231-2245

Tephra soils around mount Kupe harbor forests which have in the past 30 to 40 years been subject to degradation giving way to continuous cultivation which have the tendency to reduce the yield potentials of the soils. This study was conducted to evaluate the state of degradation following the long periods of cultivation to assist put in place more sustainable management practices. Soil samples from six profiles developed from pyroclastic materials (tephra) of Quaternary age, three from cultivated farms and three from adjacent virgin forests were studied to establish the relationships that exist between bulk density (BD) and organic carbon (OC) content and between BD and particle size. Variations of BD and OC within profiles are erratic. Soil texture is dominated by sand (64.8–81.9%), followed by clay (11.6–32.2%) and then silt (0.8–11.9%). The relationships between BD, OC, and texture indicated that BD correlates negatively with clay (r = ?0.68, p < 0.01) and OC (r = ?0.15, p < 0.01) contents but inversely with sand (r = 0.43, p < 0.05) and silt (r = 0.33, p < 0.05) contents. Relationships between these properties were better observed in virgin forests than in cultivated farmlands indicating that virgin forest systems are more stable (equilibrium is maintained since they do not incur anthropic perturbations). The high and significantly similar OM contents in both systems indicate that farming practices in the study area are sustainable and need to be maintained since they conserve OM. Results of this study will contribute to management of similar soils in tropical environments.  相似文献   

Comparison of the DIFCO and Patoc 1 slide antigens in the screening of leptospirosis   总被引：1，自引：0，他引：1  

S W Wanyangu  M F Palmer  W J Zochowski  S A Waitkins 《Comparative immunology, microbiology and infectious diseases》1987,10(2):155-161

A comparison of the Patoc 1 slide agglutination (SAT) and DIFCO slide agglutination test for the screening of leptospirosis in man, cattle and coypu (Myocastor coypus Molina) is reported. The economic costs, convenience and availability of the antigens for the tests are analysed. It is recommended that slide agglutination methods alone are not sufficient for the routine diagnosis of leptospirosis.  相似文献