LvNotch signaling plays a dual role in regulating the position of the ectoderm-endoderm boundary in the sea urchin embryo

The molecular mechanisms guiding the positioning of the ectoderm-endoderm boundary along the animal-vegetal axis of the sea urchin embryo remain largely unknown. We report here a role for the sea urchin homolog of the Notch receptor, LvNotch, in mediating the position of this boundary. Overexpression of an activated form of LvNotch throughout the embryo shifts the ectoderm-endoderm boundary more animally along the animal-vegetal axis, whereas expression of a dominant negative form shifts the border vegetally. Mosaic experiments that target activated and dominant negative forms of LvNotch into individual blastomeres of the early embryo, combined with lineage analyses, further reveal that LvNotch signaling mediates the position of this boundary by distinct mechanisms within the animal versus vegetal portions of the embryo. In the animal region of the embryo, LvNotch signaling acts cell autonomously to promote endoderm formation more animally, while in the vegetal portion, LvNotch signaling also promotes the ectoderm-endoderm boundary more animally, but through a cell non-autonomous mechanism. We further demonstrate that vegetal LvNotch signaling controls the localization of nuclear β-catenin at the ectoderm-endoderm boundary. Based on these results, we propose that LvNotch signaling promotes the position of the ectoderm-endoderm boundary more animally via two mechanisms: (1) a cell-autonomous function within the animal region of the embryo, and (2) a cell non-autonomous role in the vegetal region that regulates a signal(s) mediating ectoderm-endoderm position, possibly through the control of nuclear β-catenin at the boundary

Achieving accurate FTIR measurements on high performance bandpass filters

The sources of ordinate error in FTIR spectrometers are reviewed with reference to measuring small out-of-band features in the spectra of bandpass filters. Procedures for identifying instrumental artefacts are described. It is shown that features well below 0.01%T can be measured reliably

Stratospheric feedback from continued increases in tropospheric methane

Tropospheric concentrations of methane have increased steadily over the past ten years at an average rate of 16.5 ppbv per year, to a value in January 1988 of 1.69 ppmv. Measurements of CH sub 4 concentrations in air bubbles trapped in ice cores have shown concentrations of about 0.7 ppmv 200 years ago, with little further change for thousands of years before that. Interpolation earlier into this century suggests a concentration of about 1.1 to 1.2 ppmv in the 1940's. The only important pathway believed to be important for transfer of air from the troposphere to the stratosphere in through the tropical tropopause which is cold enough to reduce the mixing ratio of H sub 2 O in that air to about 3 ppmv. The only other major pathway for the delivery of H to the stratosphere is through the simultaneous injection of gaseous CH sub 4 in the same rising air. The formation of clouds in the stratosphere is dependent upon very low temperatures, and generally upon the amount of water vapor available. The possibility of a positive feedback exists, especially in well-oxidized methane air, that clouds are easier to form than earlier. This could mean enhancement of PSCs in both Antarctic and Arctic locations. Additional H sub 2 O in the stratosphere can also add to some of the greenhouse calculations

Measurement of atmospheric HO by a chemical method

The parameters for a chemical technique can be outlined from the following set of desirable goals: (1) sufficient conversion of tracer species A to product B that B can be measured quantitatively in the presence of A and a great excess of air; (2) specificity of reaction such that A is converted to B only by reaction with HO; and (3) sufficient sensitivity for detection that the ambient concentration of HO is not seriously perturbed by the presence of A and B. This proposed study involves finding a chemical reaction specific enough for OH, and a measurement of the product formed. What one wants is a rate constant of about 10 to the -10th power cu cm/s, so that 0.1 percent of the OH will be converted in 100 s. Laboratory studies are needed to find a reaction which will fill this bill, yielding a product in quantity sufficient for precise measurement. This is an extremely fast constant and the search may be difficult. Again there is a question of perturbing the local environment, while still providing a sensitive measurement. Also the temperature and pressure dependence of the reaction rate is a complicated function for many of these species (that is, one must use a RRKM or Troe-based picture), and must be taken into account

Laser ion source for particle accelerators

There is an interest in accelerating atomic nuclei to produce particle beams for medical therapy, atomic and nuclear physics, inertial confinement fusion and particle physics. Laser Ion Sources, in which ions are extracted from plasma created when a high power density laser beam pulse strikes a solid surface in a vacuum, are not in common use. However, some new developments in which heavy ions have been accelerated show that such sources have the potential to provide the beams required for high-energy accelerator systems

The Control of Chicken Mites and Lice

The two very common parasites, the chicken mite and the chicken louse, arc responsible for a very large part of the loss suffered annually by poultry raisers, yet they may be dealt with effectively. The symptoms for these two pests are much alike. In severe cases they are as follows: The head and comb become pale, the bird looks sickly, its feathers become ruined and may drop out, it becomes dumpish and thin, and, if it is a female; It may stop laying. Sitting hens may leave the nest; sometimes they die from the effects of these parasites. Generally, the fowls may be seen picking at their feathers as If to remove the insects. To make sure of the presence of either lice or mites, catch the birds and examine them. The lice may be found on them either day or night; the mites usually attack the chickens at night only and during the day stay In cracks In the poultry house as well as in the droppings. The following descriptions will help the poultry raiser to determine which of the pests is attacking his chickens

Risks Associated with Harvesting and Human Consumption of Two Turtle Species in New Jersey

Snapping turtles and diamondback terrapins have unique life characteristics, making their populations’ survivorship heavily dependent upon the turtles that reach sexual maturity, limiting the harvest potential of turtles and making them vulnerable to exploitation. Therefore, this research tests mercury concentrations in diamondback terrapins and snapping turtles to determine if turtle meat should require human consumption advisories, and examines transport of mercury through the snapping turtle food web by testing prey items for mercury burden and mapping food webs using stable isotope composition. Consumption of New Jersey diamondback terrapins and snapping turtles pose a health risk. 25% of Cape May and 46% of Meadowlands terrapin muscle samples surpassed the U.S. Environmental Protection Agency mercury threshold for fish consumption. For snapping turtles, Lake Wapalanne had the highest percent of turtle samples surpassing the threshold (36%), followed by Kearny Freshwater Marsh (33%) and Lake Hopatcong (28%). Based on the results of this study it is crucial to implement human consumption advisories for consumed turtle species. Neither the commercial or recreational harvest of snapping turtles in New Jersey is well understood. We therefore administered a survey to learn about current harvest practices, willingness of commercial and recreational harvesters to pay increased license fees, and their willingness to comply with new regulations. Respondents to the recreational harvest survey collected approximately 2,285 snapping turtles between 2012 and 2014. Respondents from the commercial harvesting survey reported collecting 1,506 turtles during the 2014 season. Commercial harvesters are willing to pay a higher permit price, up to $29.22, to keep their harvesting privileges. The results of this study suggest diamondback terrapin and snapping turtles pose a human consumption health risk due to elevated mercury concentrations. We suggest consumption advisories be developed for snapping turtles starting with locations of heavy harvest while advising the sensitive population to avoid the consumption of turtles. Based on the results of the harvest surveys we can suggest both recreational and commercial harvesters are willing to follow regulations in order to ensure future harvest. Harvesters are also willing to pay a higher permit price to keep their current harvesting privileges

Rearing Chicks Successfully

Rearing chicks has its serious problems, but the young brood may be brought successfully through the first six or eight weeks if these essentials are followed: Give chicks a good start by selecting strong, vigorous, well-matured breeding stock that is free from disease and has been properly housed and fed, and by properly Incubating the eggs from the stock. Make sure that hens used for brooding are free from lice and mites before the chicks are placed with them. If an artificial brooder is used, make sure That it will provide ample heat without danger of fire, That It gives the chicks a chance to get away from the heat when they want to, That it has a capacity large enough, That It Is economical In Its cost and in the fuel it uses. Remove dead chicks promptly from the brooder and bury them deeply or burn them. Mark all weak chicks so that they will never be used as breeders. Clean the brooder and disinfect it each time before it Is used and oftener If disease breaks out in flock. Do not feed chicks until they are from 48 to 60 hours old, and then only limited amounts of easily digested food for the first week. Use only clean and wholesome food and feed it only in clean dishes and litter. Provide a variety of feeds. They should contain enough of protein and ash. Ground bone furnishes ample ash and some protein; skimmed milk and buttermilk furnish abundant protein

INVESTIGATING THERAPEUTIC OPTIONS FOR LAFORA DISEASE USING STRUCTURAL BIOLOGY AND TRANSLATIONAL METHODS

Lafora disease (LD) is a rare yet invariably fatal form of epilepsy characterized by progressive degeneration of the central nervous and motor systems and accumulation of insoluble glucans within cells. LD results from mutation of either the phosphatase laforin, an enzyme that dephosphorylates cellular glycogen, or the E3 ubiquitin ligase malin, the binding partner of laforin. Currently, there are no therapeutic options for LD, or reported methods by which the specific activity of glucan phosphatases such as laforin can be easily measured. To facilitate our translational studies, we developed an assay with which the glucan phosphatase activity of laforin as well as emerging members of the glucan phosphatase family can be characterized. We then adapted this assay for the detection of endogenous laforin activity from human and mouse tissue. This laforin bioassay will prove useful in the detection of functional laforin in LD patient tissue following the application of therapies to LD patients. We subsequently developed an in vitro readthrough reporter system in order to assess the efficacy of aminoglycosides in the readthrough of laforin and malin nonsense mutations. We found that although several laforin and malin nonsense mutations exhibited significant drug-induced readthrough, the location of the epitope tag used to detect readthrough products dramatically affected our readthrough results. Cell lines established from LD patients with nonsense mutations are thus required to accurately assess the efficacy of aminoglycosides as a therapeutic option for LD. Using hydrogen-deuterium exchange mass spectrometry (DXMS), we then gained insight into the molecular etiology of several point mutations in laforin that cause LD. We identified a novel motif in the phosphatase domain of laforin that shares homology with glycosyl hydrolases (GH) and appears to play a role in the interaction of laforin with glucans. We studied the impact of the Y294N and P301L LD mutations within this GH motif on glucan binding. Surprisingly, these mutations did not reduce glucan binding as expected, rather enhancing the binding of laforin to glucans. These findings elucidate the mechanism by which laforin interacts with and acts upon glucan substrates, providing a target for the development of therapeutic compounds

VPython: 3D programming for ordinary mortals

VPython is a programming environment that enables even novices to write programs that produce navigable real-time 3D animations. One to two hours of carefully crafted instruction is sufficient to bring novice students to the point of being able to do serious computer modeling (http://www.matterandinteractions.org). VPython is based on the Python programming language (http://python.org) which has a large user community. Like Python, VPython is open source freeware available for Windows, Linux, and Macintosh (http://vpython.org). Workshop participants will learn to write 3D programs