242 research outputs found
Genu Recurvatum in Dance Training: Assessing and Addressing the Structural Deformity in Dancers
Genu recurvatum is a medical condition in which the knee curves baac kwar d past the normal range of extension predominantly in the sagittal plane. Hyperextension can be attributed to extra laxity in the body, therefore the surrounding ligaments of the knee allow for the femur and tibia to be placed past a sagittal alignment of 180°, which is the possible knee extension of normal knee alignment. Genu recurvatum, medically viewed as a deformity, is desirable and considered a positive attribute in the dance world, especially classical ballet. Hyperextension also makes the line of the leg appear longer and straighter in ballet positions. Classical ballet requires beauty in form and values length; therefore hyperextension enhances ballet\u27s visual appeal. As aesthetically pleasing and desirable genu recurvatum is in the ballet world, it remains a structural deformity, one that has many repercussions. Genu recurvatum has multiple side effects that impact dance technique, body alignment, muscular development and susception to injury. As a dancer and dance educator with genu recurvatum, it is imperative for me to devise a comprehensive explanation of the condition regarding its effects on dance training and formulate resolutions that empower the educator to address genu recurvatum early in dance education. Early detection and awareness of genu recurvatum in dance students will result in more stable, better aligned and less injury prone dancers.
So much of what makes a dancer with hyperextension a special situation to instruct is that if the instructor does not possess this structural difference, it is difficult to understand how it functions and feels. How does one effectively teach something with which they have no experience
A structural investigation of novel thiophene-functionalized BEDT-TTF donors for application as organic field-effect transistors
Three new unsymmetrical thiophene-functionalized bisIJethylenedithio)tetrathiafulvalene (BEDT-TTF) donors (1–3) have been synthesized, characterised and examined as semiconducting materials for organic field-effect transistor (OFET) devices. The X-ray crystal structures of (1) and (2) reveal both neutral donors pack as dimers with lateral S⋯S contacts. For (1) the molecules are co-facially stacked in a head-to-tail manner with some degree of latitudinal slippage. A device prepared from a crystalline thin film of (1) deposited on unmodified silicon wafer substrate displays a mobility of 5.9 × 10−3 cm2 V−1 s−1 with an on/off ratio of 11. The shorter CH2 linker in (2) results in poorer orbital overlap, likely due to significant longitudinal and latitudinal slippage between molecules in the crystal lattice. As a consequence, no field-effect response was observed for the device fabricated from (2)
Vulnerability of Illinois nature preserves to potential ground-water contamination volume I: methodology and initial assessment
"Prepared for Illinois Nature Preserves Commission.""March 1997."The Illinois Nature Preserves Commission (INPC) was created by the Illinois Natural
Areas Preservation Act in 1963 (ch. 105, para. 701 et. seq.), with the mission to
"assist...landowners in protecting high quality natural areas and habitats of endangered and
threatened species in perpetuity, through voluntary dedication of such lands into the Illinois
Nature Preserves System." Dedication as a nature preserve provides strong legal protection. For
example, penalties for damaging a nature preserve range from a Class A misdemeanor to
$10,000 per day in civil penalties. As of December 1996, the Illinois Nature Preserve System
consisted of 261 nature preserves that encompass more than 35,000 acres (14,200 hectares) in 73
of the 102 Illinois counties.
A significant threat to nature preserves (and other areas with high quality natural
communities) is adjacent land use. Variability in adjacent land use generally depends on
preserve size and location. Frequently, many different land uses surround a single nature
preserve. Potential ground-water contaminant sources include: dumping within or near a
preserve, residential septic systems, roads where deicers are used, agricultural fields or feedlots,
leaking impoundments or storage tanks, and certain industrial and commercial activities.
Unfortunately, the lack of baseline data at most preserves prevents the detection of water quality
degradation from off-site activities.
During this study, methods were developed and utilized to assess nature preserve
sensitivity and vulnerability to potential ground-water contamination. First, a shallow
ground-water sensitivity map of the state (1:500,000) was prepared using GIS techniques. It predicts the
potential for movement of contaminants from the surface into shallow ground water based on
soil leaching characteristics and depth to the uppermost aquifer. Two hundred seven nature
preserves were screened, and nearly half of them were categorized as having high or very high
sensitivity to ground-water contamination.
Second, site surveys were conducted at the 85 nature preserves, which were expected to
be most sensitive to ground-water contamination. Hydrologic, geologic, and land-use
information was collected for the sites and surrounding areas prior to the surveys. These data
were used during the surveys and can be used for future interpretations and comparisons.
Roughly 30% of the sites were classified as having moderate-to-high or high vulnerability. The
development and use of a field evaluation form facilitated site surveys and the subsequent entry
of field data into an electronic database. These types of surveys should be conducted at all nature
preserves to provide a standard set of background information for future decision making.
Third, the geology and hydrology of Spring Grove Fen Nature Preserve in McHenry
County were characterized in greater detail. Test drilling was conducted and 10 observation
wells were installed. A total of 64 sets of ground-water and surface water samples were collected
between August 1995 and October 1996 and analyzed for a minimum of 35 constituents.
Increased chloride concentrations (up to 121 mg/L) were observed in and upgradient of the
preserve. Use of deicers on nearby roads may be responsible for an increase in chloride of over
500% at well SG-1a. Low concentrations of alachlor metabolites (< 3
μg/L) were seen in
observation wells and in Nippersink Creek. Low concentrations of triazine residues (< 1 μg/L)
were also seen in Nippersink Creek. Chemical data at Spring Grove Fen supports the assessment
of the site being highly vulnerable to contamination. This type of chemical sampling is
important to establish existing water quality at preserves for comparison to future conditions.
Information collected during this study is intended to facilitate petitions for state
designation of ground water associated with a nature preserve as a Special Resource Ground
Water. As stated in the Illinois Administrative Code (Title 35, Part 620.230), Special Resource
Ground Water is: a) "demonstrably unique...," or b) "vital for a particularly sensitive ecological
system...," or c) "groundwater that contributes to a dedicated nature preserve...." Such a
designation may then provide an additional level of protection against destruction or degradation
of nature preserves
Botulinum Neurotoxin Devoid of Receptor Binding Domain Translocates Active Protease
Clostridium botulinum neurotoxin (BoNT) causes flaccid paralysis by disabling synaptic exocytosis. Intoxication requires the tri-modular protein to undergo conformational changes in response to pH and redox gradients across endosomes, leading to the formation of a protein-conducting channel. The ∼50 kDa light chain (LC) protease is translocated into the cytosol by the ∼100 kDa heavy chain (HC), which consists of two modules: the N-terminal translocation domain (TD) and the C-terminal Receptor Binding Domain (RBD). Here we exploited the BoNT modular design to identify the minimal requirements for channel activity and LC translocation in neurons. Using the combined detection of substrate proteolysis and single-channel currents, we showed that a di-modular protein consisting only of LC and TD was sufficient to translocate active protease into the cytosol of target cells. The RBD is dispensable for cell entry, channel activity, or LC translocation; however, it determined a pH threshold for channel formation. These findings indicate that, in addition to its individual functions, each module acts as a chaperone for the others, working in concert to achieve productive intoxication
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