Miracle-dz/UniFAR-FTUs huggingface dataset:
Economic Consequences of Replacing Cows with Genetically Improved Heifers

Abstract A deterministic model of the dairy herd was used to investigate optimal cow replacement rates when genetic trends in milk ranged . 0% to 1.0% per year. Optimal cow replacement rates maximizing net present value for the herd or maximizing milk sold per cow were insensitive to the extremes in genetic trends. Optimal replacement rates above a 20% involuntary removal rate indicated 0 to 3 cows among 100 should be culled on low yield for maximum net present value of herd females. Voluntary culling of 10 to 15 cows per 100 maximized milk sold per cow per year. At most an . 04% increase in genetic gain per year occurred in intermediate cow replacement rates (range 28% to 32%) relative to the extremes (20% or 39%) when the best females were selected. These intermediate rates indicated a balance between opposing effects of a declining generation interval and a decreasing selection intensity among dams as replacement rate increased. Cow replacement rates which maximize net present value of all females in the herd, including reared replacements, are lower than rates which maximize the net present value of the cow herd only.
Aggregated Drinking Behavior of Radiated Tortoises (Astrochelys radiata) in Arid Southwestern Madagascar

Abstract While conducting a monitoring program in arid southwestern Madagascar we observed a large aggregation of ca. 100 radiated tortoises (Astrochelys radiata) along ca. 80 m of dry creek bottom at the onset of the wet season. Tortoises had apparently anticipated rainfall and as precipitation ensued, immediately began drinking from small depressions in the bedrock. We discuss potential mechanisms and consequences of the behavior and compare it with similar observations in desert tortoises (Gopherus agassizii).
Search Theory and Mate Choice. I. Models of Single-Sex Discrimination

Sexual selection depends on differential patterns of mate preference and choice. Little attention has been paid, however, to the manner in which individuals acquire information about the quality of potential mates and how this information is used to form mating decisions. Different decision rules for determining mating preferences often lead to different fitness consequences for the actively searching and choosy sex. In this paper, I compare the expected fitness consequences of two alternative decision-making strategies: a best-of-n strategy (whereby searching individuals choose the best mate from a sample of size n) and a strategy based on sequential sampling (whereby the searching individual establishes a critical mate quality and continues searching until encountering a mate at or above this quality). For the same distribution of potential mate qualities, the sequential-search strategy generates higher expected fitness gains than the best-of-n strategy. This is in contrast to earlier conclusions (e.g., Janetos 1980; Halliday 1983) that the best-of-n is a dominant strategy for mate choice. In the models presented here, the cost of mate search is included; earlier models neglected this important aspect of mate choice, and this difference accounts for the different conclusions. The sequential-search model establishes a critical mate-acceptance level that equates the cost of sampling one additional potential mate and the expected fitness gain from one additional search. As the cost of search increases, the critical threshold decreases. The basic sequential-search model can be extended to include time discounting, finite time horizon, systematic search, learning, variable search costs, and mate responsiveness. In each extension, new critical thresholds for mate acceptability can be established. In some cases, such as an extension to include a finite time horizon, the critical threshold is anticipated to undergo a monotonic decline as search progresses: searchers become less choosy over time if they are unsuccessful at finding mates. The role of the arithmetic mean and variance of fitness among potential mates can be explored within these simple models. As the mean and variance of mate quality within the population increases, the critical threshold for acceptability increases. The basic model and its extensions are subject to easy empirical testing. These models will prove valuable in establishing the link between aspects of individual behavior and population-level selection processes.
Substrate and litterfall effects on conifer seedling survivorship in southern boreal stands of Canada

Most conifer seeds die as seeds or seedlings within 5 years after dispersal. Understanding what factors keep a few of them alive is essential if natural regeneration is to be maintained in managed forests. For example, decaying logs and the conifer seedlings that often grow on them are rare under certain canopies such as deciduous trembling aspen (Populus tremuloides Michx.). We conducted a seeding experiment to evaluate the role of certain substrates, and litterfall, on early conifer survivorship. Seeds of balsam fir (Abies balsamea (L.) Mill. ), white spruce (Picea glauca (Moench) Voss), and eastern white-cedar (Thuja occidentalis L.) were sown during 2 consecutive years on mineral soil, relocated logs, and litter in deciduous aspen and coniferous (Thuja occidentalis dominated) stands. Seedling survivor ship was monitored at the end of the first growing season and 1 year after each sowing. Conifer seedling survivorship was equivalent or greater under aspen than under cedar-dominated canopies. Picea and T.
Malignant cells in cerebrospinal fluid (CSF): The meaning of a positive CSF cytology

We reviewed the correlation between malignant cells in cerebrospinal fluid (CSF) (positive cytology) and pathologic findings at autopsy. The purpose was to discover: (1) the incidence of negative CSF cytology in patients with CNS malignancy, (2) the incidence of false-positive cytology, and (3) the relationship between a true-positive cytology and the distribution of malignant tumor at autopsy. Of 117 patients with CNS tumor and premortem cytologic examination of the CSF, 31 (26 percent) were positive and 86 (74 percent) were negative. Only 1 of 66 patients with tumor that did not reach the leptomeninges had a positive cytology. Of 51 patients with leptomeningeal tumor at autopsy, cytology was positive in 30 (59 percent) and negative in 21 (41 percent). Five potentially “falsepositive” cytologies were encountered: Three patients were treated, and tumor may have been eradicated; in two patients with lymphoma, inflammatory cells associated with infection were apparently mistaken for malignant cells. These data indicate that a positive CSF cytology is a reliable indicator of CNS malignancy and almost always reflects leptomeningeal tumor.
Une méthode de mesure du débit de sève brute dans de petits arbres par bilan de chaleur

it is assumed that the heat flow between the trunk surface and the surrounding air is negligible. The method was tested : a) in the laboratory, by forcing water passage in a branch segment under stationary conditions and by comparing these known water fluxes with the estimated values; b) in the greenhouse, with small potted trees (1 - 8 cm diameter), by comparing the actual transpiration rate measured by weighing and the estimated values. The experimental results indicate that the computed sap flow rate closely follows the measured transpiration rate and the daily transpiration flow is evaluated by excess with a variable error not greater than 30%. Analysis of the results shows that this method can be improved by measuring the lateral heat flow and the heat power accumulated in the volume of trunk limited by the heating jacket An improved sap flow sensor is now being tested.
Survey of Natural Enemies of Whiteflies (Hemiptera: Aleyrodidae) in Egypt with New Local and World Records

ABSTRACT Whiteflies (Hemiptera: Aleyrodidae) are some of the most problematic global pests of agricultural crops. Yet, natural enemies help control whiteflies. A field survey was conducted to identify and record the natural enemies associated with whiteflies in Egypt. Fifty-two natural enemies (29 species of parasitoids, 8 species of pathogens, and 15 species of predators) were found attacking or isolated from 14 whitefly species in Egypt. New world records are reported herein for two parasitoids [Encarsia lutea Masi and Eretmocerus mundus (Mercet)] on eight species of whiteflies, and for three predators [Chilocorus bipustulatus L. , Chrysoperla carnea (Stephens), and Coccinella septempunctata L. ] on a single whitefly species [Siphoninus phillyreae (Haliday)]. In addition, new local records of natural enemies on whiteflies are reported; this is the first local report of six predators and three entomopathogenic fungi of whiteflies in Egypt. This work helps in defining the natural enemies of whiteflies in and near agricultural communities.
The temporal correlation of changes in apoplast pH and growth rate in maize coleoptile segments

Auxin induces extracellular acidification in growing shoot tissue. The causal relationship between this process and auxin-mediated growth is debated, partly because of contradicting previous reports on the temporal correlation of auxin-induced apoplast pH-drops and growth bursts. We have simultaneously measured both parameters on the background of spontaneously occurring endogenous changes in growth rate and apoplast pH in maize coleoptile segments. Our data demonstrate good temporal correlation, during both the ‘Spontaneous Growth Response’ and the response to exogenous auxin, which is transient under the conditions chosen due to rapid auxin metabolism. We suggest that cell wall pH and growth rate are co-regulated in this organ, and that contradictions in the literature might be due to technical difficulties.
Antileishmania and Immunostimulating Activities of Two Dimeric Proanthocyanidins From Khaya senegalensis

Bioassay-guided fractionation of the bark of Khaya senegalensis (Desr.) A. Jus. (Meliaceae) led to the isolation of two dimeric proanthocyanidins, catechin-(4a,6)-catechin (1) and catechin-(4a,8)-catechin) (2), with immunostimulating activities. Their structures were determined by chromatographic and spectroscopic methods (HREIMS, EIMS, 1 H-NMR). Anti- Leishmania screening of extracts and pure compounds was conducted against Leishmania donovani, L. major, L. infantum promastigotes and retested against L. donovani amastigotes persisting in RAW macrophages as host cells. Their cytotoxicity was evaluated against three mammalian cell lines (RAW, A549 and KB). Isolated compounds (1) and (2) were not active against promastigotes (EC 50 > 25.0 µg/ml), but exhibited significant effects when tested against amastigotes indicating an indirect immunostimulating principle (EC 50 = 3.85 and 3.98 µg/mL, respectively) with no cytotoxicity.
Bacterial dynamics in the upper St. Lawrence estuary

The distribution of free bacteria in the St. Lawrence estuary was interpreted by means of bacterial fluxes and hydrodynamic residence times, derived from a circulation model, and growth and grazing rates, obtained from cultures. Bacterial abundances decreased exponentially along the salinity gradient, from 3.9 x 10 9 liter-' in freshwater to 0.5 x 10 9 liter -1 at salinity >20. The rates of growth (0.02-0.08 h -1 ) and grazing (0.01-0.09 h -1 ) were strongly correlated (r = 0.82), which suggests that bacteria tended toward a state of trophodynamic equilibrium (growth grazing). However, negative bacterial fluxes obtained from the model imply that the estuary is a sink for bacteria. Results from the circulation model and the cultures show that physical processes are important controlling factors of the distribution of bacteria and point to predation as the process causing bacterial losses in the estuary. Calculations show that small imbalances between growth and grazing can account for the observed distribution. Rates of dispersion and growth and grazing are of the same order of magnitude, which shows that biological processes are nevertheless significant relative to physical processes. Although the distribution of free bacteria appears largely under hydrodynamic control, the bacterial community is characterized by significant biological rates and can experience large transformations during estuarine transit.
Aquaporinas: de canais de água a transportadores multifuncionais em plantas

From the functional identification of the first plant aquaporin, in 1993, up to today, a lot of information about the structure, location and function of different members of this multigene family of membrane proteins was provided by the scientific community. Initially regarded as "simple water channels", the aquaporins have been shown to transport gases and small neutral solutes such as glycerol, urea and silicon, transforming the concept of transmembrane transport. Due to the redundancy of aquaporin genes and their distribution in all organs and plant tissues, these proteins have been considered essential in maintaining vital functions in plants such as water and nutrient uptake in roots, seed germination, photosynthesis, transpiration and reproduction. This work presents a review on molecular and functional characterization of aquaporins and their relevance for plant development and in response to environmental stresses. Despite advances in research on plant aquaporins, there are few studies with native species from tropical regions and therefore there is a vast field of research to be explored, given the differences in water availability, the occurrence of various environmental stresses in tropical biomes, and the mechanisms employed by plants of these regions to be adapted to the wide variety of environmental conditions.
Historical trends in tree-ring growth and chemistry across an air-quality gradient in Wisconsin

Basal-area increment and chemical composition of xylem wood were measured in three old-growth (ca. 75–100 years) white pine (Pinusstrobus L.) and three sugar maple (Acersaccharum) Marsh. ) stands across a pH and SO4 gradient in precipitation in Wisconsin. In 1986 the volume-weighted mean pH and SO4 content of precipitation ranged from 4.5 to 5.0 and from 21 to 11 kg • ha−1, respectively, from southeastern to northwestern Wisconsin. With one exception (a white pine site at Point Beach in eastern Wisconsin), basal-area increment increased from the 1890s until the 1950s (sugar maple) or 1970s (white pine), then levelled off. Growth efficiency, estimated as the ratio of basal area to exposed crown area or crown volume for the 1980–1985 period, was similar for sugar maple across the gradient; however, growth efficiency of white pine was lower at Point Beach than at the two northern Wisconsin sites. Lead concentrations in xylem wood of both species have increased with time, except at Crotte Creek in northwestern.
MATHEMATICAL MODELING OF CELL DYNAMICS AFTER ALLOGENEIC BONE MARROW TRANSPLANTATION

In this paper a basic mathematical model is introduced to describe the dynamics of three cell lines after allogeneic stem cell transplantation: normal host cells, leukemic host cells and donor cells. Their evolution is one of competitive type and depends upon kinetic and cell–cell interaction parameters. Numerical simulations prove that the evolution can ultimately lead either to the normal hematopoietic state achieved by the expansion of the donor cells and the elimination of the host cells, or to the leukemic hematopoietic state characterized by the proliferation of the cancer line and the suppression of the other cell lines. One state or the other is reached depending on cell–cell interactions (anti-host, anti-leukemia and anti-graft effects) and initial cell concentrations at transplantation. The model also provides a theoretical basis for the control of post-transplant evolution aimed at the achievement of normal hematopoiesis.
Hypoxia-inducible Factor 1α (HIF-1α) Is a Non-heme Iron Protein

The hypoxia-inducible factor 1 complex (HIF-1) is involved in the transcriptional activation of several genes, like erythropoietin and vascular endothelial growth factor, that are responsive to the lack of oxygen. The HIF-1 complex is composed of two b-HLH proteins: HIF-1β, that is constitutively expressed, and HIF-1α, that is present only in hypoxic cells. The HIF-1α subunit is continuously synthesized and degraded by the ubiquitin-proteasome under oxic conditions. Hypoxia, transition metals, iron chelators, and several antioxidants stabilize the HIF-1α protein, allowing the formation of the transcriptionally active HIF-1 complex. The mechanisms of oxygen sensing and the pathways leading to HIF-1α stabilization are unclear. Because the involvement of a heme protein oxygen sensor has been postulated, we tested the heme sensor hypothesis by using a luciferase-expressing cell line (B-1), that is highly responsive to hypoxia. Exposure of B-1 cells to carbon monoxide and heme synthesis inhibitors failed to show any effect on the hypoxia responsiveness of these cells, suggesting that heme proteins are not involved in hypoxia sensing. Measurement of iron in recombinantly expressed HIF-1α protein revealed that this protein binds ironin vivo. Iron binding was localized to a 129-amino acid peptide between sequences 529 and 658 of the HIF-1α protein. Although the exact structure of the iron center has not been yet defined, a 2:1 metal/protein molar ratio suggests a di-iron center, probably similar to the one found in hemerythrin. This finding is compatible with a model where redox reaction may occur directly in the iron center of the HIF-1α subunit, affecting its survival inoxic conditions.
Habitat partitioning among sympatric wintering Common Eiders Somateria mollissima and King Eiders Somateria spectabilis

We studied the distribution of sympatric wintering Common Elders Somateria mollissima and King Eiders Somateria spectabilis in northern Norway in relation to the water depth and substrate type. The Common Eider selected water shallower than 10 m, mainly over kelp beds and sand/rock habitats. At the darkest time of the year, Common Elders also fed much more than expected over urchin barrens. In contrast, the King Eider usually dived deeper than 20 m, and when they arrived in December, King Eiders fed especially in areas which were dominated by cobbles. Later in the season, they dispersed into areas with other substrates but still preferred deep water. The segregation between the two species was significant both for depth and substrate type, but depth was the most important factor. The change in the use of various substrate types throughout the winter was also significantly different between the two species, thus very little interspecific competition seemed to occur.
Synopsis of the genus Mitriostigma (Rubiaceae) with a new monocaulous species from south Cameroon

Mitriostigma monocaule Sonke ´ & Dessein sp. nov., a new Rubiaceae species from south Cameroon is described and illustrated. The novelty is easily separated from the other four Mitriostigma species by its monocaulous growth form, the other species being shrubs, sub-shrubs, or occasionally trees. Another typical character for the species is its supra-axillary inflorescences paired at the nodes. The novelty is related to M. barteri, from which it further differs in the somewhat larger leaves with a more pronounced acumen and a higher number of secondary veins. A first conservation status for the species is given. A synopsis of the genus Mitriostigma with a taxonomic key is also provided. Mitriostigma Hochst. is an exclusively African genus of the family Rubiaceae comprising four species. Mitriostigma axillare Hochst. , the type species of the genus, ranges from south Africa to Mozambique and probably also occurs in Tanzania. Mitriostigma usambarense Verdc. and M. greenwayi Bridson are endemic to Tanzania and Kenya, respectively, and M. barteri Hook. f. ex Hiern occurs in Equatorial Guinea (Bioko) and Cameroon (Verdcourt 1987). Mitriostigma was established by Hochstetter in 1842 and its name refers to the mitre-shaped stigma observed in M. axillare. Traditionally, the genus has been included in the tribe Gardenieae (Keay 1958, 1963, Robbrecht 1988), position confirmed by recent molecular studies (Andreasen and Bremer 1996, 2000, Robbrecht and Manen 2006). Mitriostigma is closely related to Oxyanthus from which it mainly differs in the shorter corolla tubes, the apiculate anthers, and the winged stigmatic clubs (though presumably absent in M. usambarense) (Bridson 1979, Verdcourt 1987). During recent botanical inventory work in south Cameroon the first two authors encountered an unusual Mitriostigma: a monocaul, i.e. single-stemmed, dwarf with supra-axillary inflorescences paired at the nodes, and with pinkish ovaries and calyces. This collection did not match any of the species known in the genus (Keay 1963, Verdcourt 1987, Bridson 1988), or any other specimen of Mitriostigma stored in herbaria. Our specimens resemble M. barteri in having campanulate corollas and ovoid to sub-fusiform fruits. However, it differs from all species known in the genus by its monocaul growth form and the supra-axillary inflorescences paired at the nodes. We therefore here propose a new species, i.e. Mitriostigma monocaule. In addition, as there is no document dealing with all the Mitriostigma species, we include a synopsis of the genus.
Fate and Transport of Nitrogen Applied to Six Warm‐Season Turfgrasses

A greenhouse study compared six warm season turfgrasses [common bermudagrass [Cynodon dactylon (L.) Pers. ], Tifway' hybrid bermudagrass (C. dactylon x transvaalensis), centipedegrass (Eremochloa ophiuroides (Munro) Hack. ), Raleigh' St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], 'Meyer' zoysiagrass (Zoysia japonica Steud.), and Emerald' zoysiagrass (Z. japonica x tenuifolia)] for NO 3 -N leaching and N use efficiency. Sod was established in sand-filled columns and managed under worst-case conditions to promote nitrate leaching. Ammonium nitrate was applied at 50 kg N ha -1 on seven dates, with the final application labeled with 15 N. Leachate samples were collected and analyzed for NO 3 -N and NH 4 -N and clippings were analyzed for total N. Leaching losses were high following the first N application, ranging from 48 to 100% of the NO 3 -N and 4 to 16% of the NH 4 -N applied. Nitrate loss from subsequent applications was reduced substantially, while NH 4 leaching was essentially eliminated. There were significant differences among species for leachate NO 3 -N concentration and cumulative N leached, with St. Augustinegrass being the most effective and Meyer zoysiagrass the least effective at minimizing NO 3 leaching. Nitrogen recovery by the turf ranged from 63% for Meyer zoysiagrass to 84% for hybrid bermudagrass. Root length density (RLD) varied significantly among species at depths >30 cm, and was negatively correlated with NO 3 leaching loss. These results document differences between the warm season turfgrasses for NO 3 leaching potential, possibly related to root distribution, and emphasize that species selection is an important factor in minimizing environmental impacts from turfgrass management.