Using Cover Crops to Suppress Weeds and Improve Soil Health

Herbicide-resistant weeds are creating challenges for producers to control weeds in crop fields. This study explores the potential of cover crops to reduce weed pressure and im­prove soil health. Cover crops were planted after corn harvest in tilled and no-till fields, and included Graza radish, winter wheat, annual ryegrass, spring oats, winter oats, and forage collards. The control was fallow with herbicide application but no cover crop. Soil health was determined prior to cover crop termination. Graza radish and forage collards did not grow consistently in all plots due to poor germination and winter kill. Significant weed biomass was produced in the fallow plot or in plots with poor cover crop stands. Microbial biomass was much greater in the no-till field than in the tilled fields

Using Cover Crops as an Effective Weed Control Method in Southeast Kansas

Weed control is important to optimize crop production. This study was conducted to compare the effectiveness of different methods of fall-implemented weed control strategies. These strategies included different cover crop mixes, chemical control, and mechanical control. The cover crop mixes included four different commonly-planted winter cover crops. The chemical control was a fall-applied burndown, and the me­chanical control was vertical tillage. We found cover crop mixes that contained cereal rye provided the most weed control, with the chemical control being a close second. Spring oats die during the winter because of the low temperatures. The three cover crop mixes containing spring oats still provided 50% reduction in weed biomass the follow­ing spring. However, the fall tillage increased the amount of weed biomass

Demography and Life Histories of Sympatric Patas Monkeys, Erythrocebus patas, and Vervets, Cercopithecus aethiops, in Laikipia, Kenya

Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. Patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation

Tensile Properties of the Murine Ventral Vertical Midline Incision

In clinical surgery, the vertical midline abdominal incision is popular but associated with healing failures. A murine model of the ventral vertical midline incision was developed in order to study the healing of this incision type.The strength of the wild type murine ventral abdominal wall in the midline was contained within the dermis; the linea alba made a negligible contribution. Unwounded abdominal wall had a downward trend (nonsignificant) in maximal tension between 12 and 29 weeks of age. The incision attained 50% of its final strength by postoperative day 40. The maximal tension of the ventral vertical midline incision was nearly that of unwounded abdominal wall by postwounding day 60; there was no difference in unwounded vs. wounded maximal tension at postwounding day 120.After 120 days of healing, the ventral vertical midline incision in the wild type mouse was not significantly different from age-matched nonwounded controls. About half of the final incisional strength was attained after 6 weeks of healing. The significance of this work was to establish the kinetics of wild type incisional healing in a model for which numerous genotypes and genetic tools would be available for subsequent study

Metachronous Bilateral Testicular Leydig-Like Tumors Leading to the Diagnosis of Congenital Adrenal Hyperplasia (Adrenogenital Syndrome)

A 33-year-old male with a history of left testis Leydig cell tumor (LCT), 3-month status after left radical orchiectomy, presented with a rapidly enlarging (0.6 cm to 3.7 cm) right testicular mass. He underwent a right radical orchiectomy, sections interpreted as showing a similar Leydig cell-like oncocytic proliferation, with a differential diagnosis including metachronous bilateral LCT and metachronous bilateral testicular tumors associated with congenital adrenal hyperplasia (a.k.a. “testicular adrenal rest tumors” (TARTs) and “testicular tumors of the adrenogenital syndrome” (TTAGS)). Additional workup demonstrated a markedly elevated serum adrenocorticotropic hormone (ACTH) and elevated adrenal precursor steroid levels. He was diagnosed with congenital adrenal hyperplasia, 3β-hydroxysteroid dehydrogenase deficiency (3BHSD) type, and started on treatment. Metachronous bilateral testicular masses in adults should prompt consideration of adult presentation of CAH. Since all untreated CAH patients are expected to have elevated serum ACTH, formal exclusion of CAH prior to surgical resection of a testicular Leydig-like proliferation could be accomplished by screening for elevated serum ACTH

The influence of rearing conditions on maternal behavior in cynomolgus macaques (Macaca fascicularis)

Contains fulltext : 28348.pdf (publisher's version ) (Open Access)We studied the influence of rearing on the adequacy of maternal behavior by comparing 20 harem-reared and 15 peer-reared primiparous cynomolgus monkeys. We used them plus 11 wild-caught females to extend this comparison to multiparous subjects and also to compare primiparae with multiparae. We observed no behavioral effect of rearing and parity. Primiparous maternal adequacy amounted to 93% in peer-reared subjects and to 95% in harem-reared monkeys. We extensively discuss theories concerning rearing effects. Leitmotifs throughout the discussion are survival value of maternal behavior immediately after parturition and predictive value of this behavior for the further course of maternal behavior. Support is accumulated for the hypothesis that certain tactile and visual experiences suffice for the development of adequate maternal behavior