Experimental Hybridization of Northern Chihuahuan Desert Region Opuntia (Cactaceae)

Possible natural hybridization among 11 taxa of Opuntia sensu stricto was investigated in the northern Chihuahuan Desert region through the use of experimental hybridization. Established plants representing specific taxa growing in the Sul Ross State University Opuntia garden were used for all experiments. Reciprocal crosses were made between putative parental taxa of field-observed putative hybrids, and each experimental cross analyzed for fruit and seed set. For each taxon, tests were performed to control for possible apomictic, autogamous, and geitonogamous seed set. Several experimental crosses were found to set seed in amounts expected for natural pollination events. Data gathered from the tests also provided basic information regarding the breeding systems of the taxa investigated. Data presented here provide support for several hypothesized hybridization events among Opuntia

Highly-functionalised difluorinated cyclohexane polyols via the Diels–Alder reaction : regiochemical control via the phenylsulfonyl group

A difluorinated dienophile underwent cycloaddition reactions with a range of furans to afford cycloadducts whichcould be processed regio- and stereoselectively via episulfonium ions, generated by the reaction between their alkenyl groups and phenylsulfenyl chloride. The oxabicyclic products were oxidised to the phenylsulfonyl level and ring opened via E1CB or reductive desulfonative pathways to afford, ultimately, difluorinated cyclohexene or cyclohexane polyols

Propagation of Cycad Collections from Seed

Propagation of cycads from seed can aid their conservation as it helps reduce the demand for wildcollected plants. Seed-produced plants can be used for reintroduction programmes if the parent plants are from known provenance and care is taken to avoid hybridisation. This paper discusses the techniques required for successful seed propagation of cycads, including pollen collection, storage, viability testing, manual pollination, seed collection, storage and germination

Social Media and Professional School Counselors: Ethical and Legal Considerations

The use of social media continues to expand in prevalence and is a medium of communication for individuals of all ages. Schools are using social media to engage their stakeholders at increasing rates. Therefore, school counselors require the knowledge and appreciation of ethical and legal issues regarding the use of such technology. The purpose of this manuscript is to: (a) introduce the development and prevalence of social media; (b) review legal and ethical issues related to social media use in schools; and (c) present strategies in which school counselors can engage in ethical interactions via social media

Seed predation by insects across a tropical forest precipitation gradient

1. Pre‐dispersal predation of seeds by insects can be an important source of plant mortality, with consequences for plant population dynamics and community diversity. 2. The intensity and host‐specificity of natural enemies, including seed predators, is predicted to vary systematically across environmental gradients. These trends could contribute to large‐scale patterns in diversity, such as the widely observed positive relationship between plant species richness and precipitation. However, fundamental information on inter‐ and intraspecific seed predation is lacking at the landscape scale. 3. We assessed the intensity of seed predation by insects at eight forest sites spanning a steep precipitation and plant species‐richness gradient in Panama. We dissected freshly abscised fruits and seeds of woody plants to measure rates of predation, and assessed host‐specificity by rearing insects from them. 4. On average, 22.6% of dissected seeds were predated across 31 host species. Species‐specific and site‐level seed predation rates and the number of seed predator species reared per host were not significantly associated with annual rainfall or dry season water deficit. 5. In total, 45 seed predator morphospecies were reared from seeds of 16 plant species. Host‐specificity was high, with 91% of seed predator morphospecies associated with just one plant species. 6. Our results support evidence that pre‐dispersal insect seed predators are highly host‐specific and exhibit great intraspecific, interspecific and landscape‐scale (i.e. between‐site) variation in seed predation intensity. Host‐specific seed predators, particularly those causing moderate to high seed predation rates, could influence plant population dynamics and local community structure

Schaffnerella Rediscovered! (Gramineae, Chloridoideae)

From 1876 to 1880 in San Luis Potosí, Mexico, J. G. Schaffner made the first collections of a small grass that later was named Schaffnerella gracilis (Chloridoideae). The monotypic genus apparently was not encountered again by botanists until 2001, when, during a targeted search, we discovered it in the Sierra de San Miguelito growing along the Río Potosino, ca. 6 air km southwest of the city of San Luis Potosí. Most of the 100-150 plants encountered along a 3-km stretch of the Río Potosino above the village of Escalerillas and reservoir EI Potosino were growing in a moist alluvium of rock and sand. Historically known to occur some 10 km or more downstream near Morales, a village at the western edge of the city of San Luis Potosí, S. gracilis has been impacted adversely by the creation of dams. Much additional field work is required to determine the geographic range and frequency of the species. Also needed are life history and population-level studies

X-ray Evaluation of the Marshall Grazing Incidence X-Ray Spectrometer (MaGIXS) Nickel-Replicated Mirrors

X-ray observations of astronomical objects provides diagnostics not available in any other wavelength regime, however the capability of making these observation at a high spatial resolution has proven challenging. Recently, NASA Marshall Space Flight Center (MSFC) has made good progress in employing computer numerical control (CNC) polishing techniques on electroless nickel mandrels as part of our replicated grazing incidence optics program. CNC polishing has afforded the ability to deterministically refine mandrel figure, thereby improving mirror performance. The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a MSFC-led sounding rocket instrument that is designed to make the first ever soft x-ray spectral observations of the Sun spatially resolved along a narrow slit. MaGIXS incorporates some of the first mirrors produced at MSFC using this polishing technique. Here we present the predicted mirror performance obtained from metrology, after completion of CNC polishing, as well as the results of X-ray tests performed on the MaGIXS telescope mirror before and after mounting

Perennial Warm-Season Grass Forages Impact on Cow-Calf Profitability in the Fescue Belt

Incorporating a perennial warm- season grass (WSG) into tall fescue (Lolium arundina-ceum [Schreb.] Darbysh.) forage systems in the fescue belt can help avoid the effects of fescue toxicosis on beef cattle (Bos taurus) reproduction and animal performance and provide forage during summer when fescue production is low. However, little information is available on the economics of incorporating WSG into fescue-based forage systems. We developed a simulation model to compare profitability of three forage systems—100% tall fescue, 70% tall fescue/30% bermudagrass (Cynodon dactylon), and 70% tall fescue/ 30% switchgrass (Panicum virgatum)—while also comparing spring- and fall-calving sea-sons on model beef cattle cow-calf operations in the fescue belt. Incorporating switch-grass increased profitability of tall fescue forage systems in both spring- and fall- calving herds, while adding bermudagrass increased profitability in spring-calving herds but not fall-calving herds. Spring-calving herds benefited the most from incorporating WSG, with profitability increases of $877 and$372 per hectare for switchgrass and bermudagrass, respectively, over the 100% tall fescue system. The order of profitability of forage systems did not change with randomly simulated decreases in rainfall and associated increased hay- feeding days, but with annual rainfall \u3e88% of the long- term average, fall- calving 100% tall fescue was more profitable than fall- calving 70% tall fescue/30% bermuda grass. Of the scenarios modeled, the results of the simulation suggest that a profit-maximizing producer would utilize a 70% tall fescue/30% switchgrass forage system

Development of Drugs for Nontuberculous Mycobacterial Disease:Clinicians’ Interpretation of a US Food and Drug Administration Workshop

The US Food and Drug Administration convened a workshop to discuss clinical trial design challenges and considerations related to the treatment of nontuberculous mycobacterial pulmonary disease, to include topics such as clinical trial end points, duration, and populations. The clinicians participating in the meeting provide here their interpretation of the discussion, which included US Food and Drug Administration and industry representatives. The treatment of nontuberculous mycobacterial pulmonary disease typically includes multiple antibiotics for a prolonged period and can be difficult to tolerate; there is a great need for new treatment options. Most individuals have a microbiologic response to therapy, but data correlating decreasing bacillary load with patient-reported outcomes or measured functional improvement are lacking. Accordingly, trial designs for new therapeutic agents should incorporate both microbiologic and clinical outcome measures and select appropriate study candidates with capacity for measurable change of such outcome measures. The need for shorter study designs, early primary end points, and placebo control arms was highlighted during the workshop