longicornisKB five calculation runs were done for 5, 10, 12.5, 15 and 20°C at different food levels. The impact find more of temperature on growth rates was defined by the function

fte, which at lower temperatures (< 15°C) is described by Q10 and at higher ones by the parabolic threshold function ft2. The growth rate of T. longicornisKB increases rapidly with rising temperature in the 5–15°C range but less so with a food concentration from 25 mgC m−3 to excess. But the growth rates for the model stages were nearly equal at both 15°C and of 20°C according to the function fte. Figure 5 shows that the optimum temperature for the development of T. longicornis is slightly higher than 15°C. In the real environment during summer, in the 15–20°C temperature range, and probably with limited food availability, an increase in temperature reduces growth of almost all developmental stages. The growth rate of T. longicornisH at 12.5°C in the 25–200 mgC m−3 range of food concentration was also obtained here after data given by Harris and Paffenhöfer, 1976a and Harris and Paffenhöfer, 1976b. If we compare our results of g for T. longicornisKB at 12.5°C to the same stage groups as in their studies and assume that N1 does not grow, it appears that those authors www.selleckchem.com/products/GDC-0449.html probably found values similar to (Temora) or higher than (Pseudocalanus) those found by Klein Breteler et al. (1982) at the same food concentration

and temperature (see pp. 205–206 in Klein Breteler et al. 1982). The values of g for T. longicornisH except the naupliar stages are higher than those for T. longicornisKB at 12.5°C, which were computed using the equation given by Hirst et al. (2005) and according to the Q10 coefficient. On the basis of the findings and analysis in this study, differences in g are found between the two species and are smaller if the correction by Hirst et al. (2005) is included. The growth rate of T. longicornisH is from 1.15

to 2.4 times higher than g for T. longicornisKB and depends on development stage and food concentration; for example, for early copepodids assuming Dapagliflozin Food = 200 mgC m−3, g is equal to 0.43 day−1 and 0.374 day−1, and for Food = 25 mgC m−3, g is equal to 0.24 day−1 and 0.121 day−1 respectively. It is more probable that the difference between the results found by these authors is explained by the different algae used as food and other conditions of the experiments. The quality and quantity of food available to copepods is very important for their growth and development. In natural conditions copepod diets are selective and diverse. Selectivity by copepods may relate to the size of the prey (Atkinson 1995), its toxicity (Huntley et al. 1986) and nutritional quality (Houde & Roman 1987). Copepods often consume not just phytoplankton but heterotrophic flagellates and ciliates, detritus and other metazoans, and they can feed cannibalistically (Hirst & Bunker 2003).

, 1966 and Ferguson and Good, 1980). With the restriction of weak complexing capacity monophosphate buffers with potassium or sodium as counter ions are broadly applicable. As already mentioned above, the capacity range of buffers is narrow, comprising two pH units at best. If a broader range is required, e.g. for analysing the pH dependence of an enzyme, several buffer systems may be combined. This is, however, an unsatisfactory procedure, due to the varying activities of the enzymes

in different buffers. In such cases universal buffers, like the Teorell–Stenhagen and the Britton–Robinson buffer, consisting of more than two components and covering a broad pH range, should be used (Bisswanger, 2011 and Teorell and Stenhagen, 1939). Finally it must be considered that dissociation click here of compounds and, consequently, also of buffers, depends strongly Angiogenesis chemical on

the temperature. Therefore the pH changes with the temperature and for exact pH specification the prevailing temperature must be indicated. Usually 20 °C is used as standard temperature for buffers and the pKa values refer to this temperature. According to the cellular milieu water is the standard solvent for enzyme assays. Only for special cases, like enzymes connected with the membrane, e.g. lipases, apolar organic solvents are used, while such solvents will denature most enzymes. However, for some enzyme assays organic solvents cannot be completely avoided, e.g. when an essential component, like a substrate, is sparingly soluble in water. It must be dissolved in higher concentration in an organic, water-miscible solvent, like ethanol, DMSO or acetone. An aliquot Phospholipase D1 of this solution is added to the assay mixture, where it should remain dissolved in its final concentration. To keep the concentration of the organic solvent in the assay mixture as small as possible the volume of the aliquot should be rather small.

In such cases the problem arises that smaller volumes require a higher concentration of the component in the organic solvent and it may immediately precipitate upon addition to the aqueous assay mixture. To prevent precipitation either the final concentration of the weakly soluble compound in the assay mixture must be kept rather low, or the fraction of the organic solvent in water must be higher to mediate solubility. So the ratio of the organic solvent in the assay mixture is directly connected with the concentration of the weakly soluble compound and sometimes lower concentrations than effectively required must be accepted. Further it has to be considered that solubility depends strongly on temperature, e.g. the compound can be just soluble at the assay temperature, but may precipitate if the assay mixture is kept in the cold before testing.

The authors acknowledge the subjects, researchers, sponsors, and the entire KDHS team that participated in the 1998, 2003, and 2008-2009 surveys. The authors declare that they have no competing interests. “
“Amaranth has recently become a focus of interest for its high nutritive values and great potential as a functional food given its cholesterol-lowering effect observed in animal models (∗Mendonça et al., 2009 and ∗Plate and Arêas, 2002). Despite its nutritional and health importance, amaranth flour has not gained sufficient research attention to its physicochemical properties. Nevertheless, some hydration and thermal properties

of individual amaranth components (protein, fiber, starch) have been widely discussed in the literature (Kong et al., 2009 and Martínez

and Añón, 1996; PI3K inhibitor Repo-Carrasco-Valencia, Peña, Kallio, & Salminen, 2009). Studies investigating the properties of amaranth flour are scarce, e.g. examining it as a complex system. It is known that the extrapolation of data on individual components to infer the behavior of more complex systems such as flours can be misleading because interactions among components could be overlooked (Sandoval, Nuñez, Muller, Della Vale, & Lourdin, 2009). While the native flour presents a particular selleck chemicals llc behavior, cooked flour could be more advantageous for application in food products due to its instantaneous characteristics. In order to obtain cooked flour, thermoplastic extrusion can be used. This is a versatile and very efficient technology, widely used in grain processing and has become a well established industrial technology, with a number of food and feed applications (Cheftel, 1986). A wide range of thermo-mechanical and thermo-chemical processes are involved, including shear, Maillard reactions, starch gelatinization, protein denaturation and click here hydrolysis. These processes result in the physical, chemical and nutritional modification of food constituents (Arêas, 1992). Moreover, the extrusion of amaranth resulted in a ready-to-eat snack with a better nutritional value compared to traditional snacks

made from maize (∗Chávez-Jáuregui et al., 2000 and Chávez-Jáuregui et al., 2003). Only a few studies have reported the extrusion cooking of pure amaranth or of amaranth blended with other grains. Despite this lack of data, extruded amaranth flour may possibly serve as a useful alternative in highly nutritious food products and could also improve the physicochemical, functional and sensory characteristics of products. In addition, the functional properties of native and extruded amaranth flour have not been reported. Against this background, the present investigation was undertaken to examine hydration and thermal properties of native and extruded amaranth flour in order to identify their potential application as food ingredients.

9 ms and TR=23 ms) preceded by a 15° FE pulse, resulting in a 135-ms low-resolution acquisition window. The resolution was 4.8×4.8×3 mm at 261×261×24 mm field of view, reconstructed to 0.5×0.5×1.5 mm. Each high-resolution segment consisted of two interleaves of a 75-interleave 3D center-out spiral acquisition with eight through-plane phase encode steps. The first interleaf of each segment was acquired with a 45° WE pulse and the second with a 90° WE pulse. Each interleave consisted of 4096 points acquired over 10 ms (TE=3.4 ms and TR=1 RR interval). A spatial saturation pulse was applied to the chest wall immediately prior to the high-resolution imaging segment in order to minimize artifacts from structures not moving

with the coronary artery. The high-resolution data were temporally located in the subject-specific right coronary rest period. Where possible, the low-resolution FDA-approved Drug Library clinical trial data were also acquired during this period of minimal motion, but the timing of the high-resolution data was prioritized. As the low-resolution data are acquired in a reverse-centric kz phase order, the effect of any motion during the low-resolution acquisition is expected to be minimal. The total acquisition duration was 300 cardiac cycles (assuming 100% respiratory efficiency) or 5 min (with a heart rate of 60 beats/min). The acquired resolution was 0.7×0.7×3 mm over a 570×570×24

mm field of view which was reconstructed to a 0.7×0.7×1.5 mm pixel size. The high field of view was Cyclic nucleotide phosphodiesterase used to bolster signal to noise ratio (SNR) in the images and to move any characteristic spiral artifacts selleck compound away from the anatomy of interest. The high-resolution acquisition window was 35 ms. All images were reconstructed and processed offline using in-house software written in MATLAB 2009a (The Mathworks, Natick, MA). Beat-to-beat 3D respiratory displacement of the right coronary artery was determined using a 3D local normalized subpixel cross-correlation of the low-resolution volumes acquired in each cardiac cycle. An end

expiratory volume was chosen as a reference using the diaphragmatic navigator information. A cuboid-shaped reference region around the coronary origin was defined on the reference volume, aided by a colored overlay of the fat image on the uncorrected high-resolution water image, as seen in Fig. 3. A search region was also defined on this volume and copied to the other low-resolution volumes for the subsequent beat-to-beat cross-correlation. In order to determine the appropriate dimensions for the search region, the cross-correlation was initially performed on a subset of 20 of the low-resolution volumes before performing the full procedure. The two high-resolution spiral interleaves acquired in each cardiac cycle were corrected [2] for respiratory motion using the 3D beat-to-beat translations obtained, and high-resolution images were reconstructed using a standard gridding [27] and fast Fourier transform technique.

Para uma melhor acurácia na avaliação da deglutição, a VFS pode ser combinada à manometria faríngea5 and 38, possibilitando a investigação entre diferentes alterações, como exemplo, a relação entre alterações na abertura do esfíncter superior do esôfago, a redução da movimentação laríngea e a falta de contração em faringe, o que, em situação clínica, inviabilizaria a compreensão de qual mecanismo afetaria o outro39. Uma nova técnica de avaliação modificada pelo bário, a VFS digitalizada, é eficaz para quantificar as alterações da deglutição40. O profissional especialista em deglutição geralmente realiza e/ou acompanha KU-57788 a realização do exame, podendo detectar a consistência alimentar mais segura e apropriada

para ser utilizada pelo paciente6 and 41. A avaliação da efetividade de estratégias facilitadoras na reabilitação da disfagia, como mudanças posturais de cabeça, manobras compensatórias, modificações do bolo CX-5461 purchase alimentar, dentre outras, podem ser testadas durante o procedimento30, 42 and 43, assim como os resultados

pós-terapêuticos44 and 45. A possibilidade do planejamento do tempo e custo do tratamento dos pacientes é outra vantagem da VFS46. Entretanto, nem sempre há um consenso entre os profissionais quanto ao uso da terminologia na descrição da fisiologia da deglutição e também nos achados do exame47. Em virtude disso, programas de análise computadorizada de imagem têm sido desenvolvidos com intuito

de aumentar a confiabilidade entre os examinadores na descrição dos componentes avaliados7. É recomendável que o tempo de exposição à radiação não exceda 2 minutos devido ao efeito biológico cumulativo em tecidos vivos47 and 48. Estudos apontaram, entretanto, que a gravidade da disfagia, além da pouca experiência see more clínica do profissional, influencia significativamente o tempo de exposição à radiação49. Outras limitações da VFS seriam a impossibilidade, em alguns casos, em manter o paciente posicionado22, e a mistura do bário ao alimento, alterando as suas características naturais50. O exame videofluoroscópico é realizado em seriógrafos, angiógrafos e arcos em C. A disponibilidade de saída adicional no monitor destes equipamentos permite que as imagens fluoroscópicas sejam captadas e registradas em mídia magnética51. O registro deve ser feito em pelo menos 30 quadros por segundo. Fornece uma imagem bidimensional, associando o raio-X às diferentes densidades das estruturas avaliadas52. A utilização de um relógio acoplado ao equipamento é necessária, permitindo a mensuração das imagens em tempo real e possibilitando avaliar a duração dos eventos. É importante a proteção do profissional e paciente com avental de chumbo, protetor da glândula tireoide, óculos e luva com chumbo53. As imagens radiográficas são visualizadas em um monitor e a gravação é realizada simultaneamente em fita VHS ou em forma digital25.

4) twice. After fixing and sectioning, cells were dehydrated via ethanol and stained with 5% uranyl acetate for 30 min followed by Reynold’s lead citrate incubation [27]. Stained cells were examined under JEOL 2100F transmission electron microscope. The presence of INPs and CSO-INPs in mitochondria surface and matrix was further confirmed by the TEM-EDS elemental analysis (TEM, JEOL 2100F). For apoptosis analysis HeLa, A549 and Hek293 cells were seeded at the density of 1 × 105 cells/well and incubated at 37 °C for 24 h. Cells were treated

with 4 μg/μl of INPs and CSO-INPs respectively for 48 h. Cells were trypsinized using 1× trypsin–EDTA and LGK-974 solubility dmso pooled in 1.5 ml tube, washed with 1× PBS buffer. Cells were resuspended Epigenetics Compound Library in 500 μl of 1× Annexin binding buffer [10× buffer composition: 0.1 M Hepes/NaOH (pH 7.4), 1.4 M NaCl, 25 mM CaCl2], 1 μl of Annexin V-FITC reagent used from stock (final

concentration 1 μg/ml). Stained samples were gently mixed and incubated at 37 °C for 10–20 min in dark [28]. FL1 channel was applied for detecting Annexin V-FITC staining through flow cytometry (BD Biosciences) with excitation wavelength 488 nm. Fluorescence spectra were analyzed by FCS 4 Express Flow Cytometry software. Mitochondrial membrane potential was analyzed by JC-1 probe (5,5,6,6-tetrachloro-1,1,3,3-tetraethyl-benzimidazolylcarbocyanine iodide) staining [29] and [30]. HeLa, A549 and Hek293 cells (1 × 105 cells/well) were harvested after 48 h exposure of 4 μg/μl iron oxide nanoparticles and chitosan oligosaccharide coated iron oxide nanoparticles (CSO-INPs) and centrifuged at 400 × g for 5 min. Cell pellet was resuspended in 0.5 ml of JC-1 solution

(10 μg/ml) for 10 min. Cells were washed with 1× PBS buffer. Mitochondrial depolarization is identified by reduction of the red/green fluorescence ratio. Green fluorescence DCLK1 (monomers) was observed through FL1 channel with almost 10,000 events of each sample using flow cytometry (BD Biosciences) with excitation at 488 nm wavelength. Fluorescence spectra were analyzed by FCS 4 Express Flow Cytometry software. Analysis of ROS production was carried out using the method reported by Mancini et al. [31], with slight modification. HeLa, A549 and Hek293 cells (1 × 105 cells/well) were seeded and incubated at 37 °C in CO2 incubator for 24 h. The cells were treated with 4 μg/μl iron oxide nanoparticles (INPs) and chitosan oligosaccharide coated iron oxide nanoparticles (CSO-INPs) respectively for 48 h. Cells were trypsinized with 1× trypsin–EDTA, and centrifuged at 1000 rpm for 5 min. Cells were washed twice with 1× PBS buffer (pH 7.4) followed by 1 h incubation in DCFH-DA (10 μmol/l) in FBS-free DMEM medium. Cells were resuspended in 1× PBS buffer, subjected to flow cytometry analysis. Finally, fluorescence spectrum was measured by flow cytometry (BD Biosciences) at 488 nm excitation and emission at 530 nm wavelength for DCFDA with 10,000 events of each sample.

Misconceptions about timing of return http://www.selleckchem.com/products/ly2109761.html to fecundity and factors affecting postpartum pregnancy risk can lead to delays in timely contraceptive initiation [4]. This study is a sub-study of the Healthy Fertility Study (HFS),2

which was conducted in Sylhet District in northeastern Bangladesh [8]. In Sylhet District, in 2011, almost half (46.5%) of non-first births occurred at short intervals of less than 36 months since the previous birth [9]. Under-five and neonatal mortality and total fertility are higher, and contraceptive prevalence is lower in Sylhet Division compared to the rest of Bangladesh [9]. HFS promoted optimal pregnancy spacing by integrating postpartum family planning (PPFP) within a community-based maternal and newborn health program. Within HFS, female community health workers (CHWs) counseled women on PPFP and provided contraception to women during household visits. Community mobilizers convened group discussion sessions with women, husbands, mothers/mothers-in-law, and other community members. In order to address noted gaps in PPFP knowledge and understanding,

the HFS study team developed a leaflet including “Asma’s Story” and a pictorial on one side, and critical messages about return to fecundity on the reverse. The leaflet and story (Fig. 1) were shared and discussed with women during counseling sessions with postpartum women and group meetings with mothers-in-law, Epigenetics inhibitor postpartum women, and men. Asma’s Story tells how one woman (“Asma”) incorrectly assessed her risk of pregnancy to be minimal during the months before her menstruation returned. Asma says she will wait until her menstruation

returns before starting a modern FP method, but then becomes pregnant. She learns that conception can occur until before menstruation returns, and it is important to start using an FP method soon after giving birth. This study was designed to assess: knowledge and perceptions regarding return to fecundity among postpartum women, husbands, and mothers/mothers-in-law; short-term outcomes of efforts to raise awareness about postpartum return to fecundity and encourage PPFP use; and the ways in which the approach may have affected postpartum women’s progression along the steps to behavior change (SBC) continuum toward modern contraceptive use. The study aimed to contribute to emerging global knowledge about behavioral approaches for PPFP in order to inform future efforts in Bangladesh and globally. Postpartum women were the main respondents for this study. Focus groups with husbands and mothers/mothers-in-law were also included with the understanding that decisions about contraceptive use are not necessarily taken by the woman alone. Formative research conducted at the outset of HFS identified husbands and mothers/mothers-in-law as key influencers of FP decisions [10].

Protein concentration was measured by the Bradford method [55], using BSA as the standard. The fraction containing mono-PEG-StAP3 species was the employed for biological studies. Prior to assays, this fraction was dialyzed against 20 mM Tris–HCl pH 8, for 48 h at 4 °C, using a cellulose membrane (Sigma D9652-100) to remove DTT and SDS. selleck chemicals The fraction was then stored at −20 °C for further analyses. To evaluate the effect of mono-PEG-StAP3 on the germination of F. solani spores, in vitro bioassays were performed as described by Guevara et al. [26]. To quantify the effect of mono-PEG-StAP3 on spore germination, the bioassays were examined by observation of four fields in Neubauer camera with a bright-field microscope. The results

from three independent experiments were analyzed to calculate the percentage of inhibition. B. cereus and E. coli were grown in Luria–Bertani selleckchem medium at 37 °C with continuous shaking to exponential phase. The bacteria were harvested from broth by centrifugation at 3500 rpm for 10 min, washed and resuspended in sterile PBS at a concentration of 104 c.f.u./ml. The concentration of bacteria was verified and quantified by culture on sheep blood agar plates. One hundred microliters of bacterial suspension were plated on 96-well polystyrene microtiter plates (BD Biosciences), and serial dilutions of mono-PEG-StAP3 were added to individual wells in triplicate and incubated for 6 h at 37 °C

with rocking. Bacteria were subsequently dispersed and aliquots were plated on blood agar plates to obtain colony counts. Pathogen viability after protein treatment was determined from the number of colonies obtained on the buffer-treated control plates compared to the number of colonies from protein-treated samples. The half maximal inhibitory concentration

(IC50) was calculated as the concentration of protein required to inhibit microbial growth by 50%. F. solani spores were incubated overnight at 25 °C with water as control or exposed to different Elongation factor 2 kinase amounts of mono-PEG-StAP3, as described by Guevara et al. [26]. SYTOX Green probe (Molecular Probes) was added to a final concentration of 0.5 μM and qualitative detection of SYTOX Green uptake was performed. After 30 min incubation, the fluorescence of the sample was observed with a Nikon Eclipse E200 fluorescence microscope (Nikon, Tokyo, Japan) equipped with a B-2A Fluorescein filter set. Positive controls included spores treated with 0.5% (w/w) Triton X-100. Fluorescence was measured using a FluorosKan Ascent (Thermo Electron Corporation, Finland) fluorescence measurement system at an excitation wavelength of 480 nm and an emission wavelength of 530 nm. Fluorescence values were corrected by subtracting the fluorescence value of a buffer incubated with SYTOX Green. Fresh human red blood cells (hRBC) were rinsed in PBS, centrifuged for 10 min at 800 rpm three times, and resuspended in PBS to a final erythrocyte concentration of 4% (v/v).

Their task was to consult two sets of clinical reports, each presenting the medical history of a cancer patient, and to answer ten questions about the patients’ condition. They were asked to perform this task in the context of a consultation they were about to have with a cancer patient who had been newly referred to them. Their task, then, was not to make a diagnosis or any other evaluation of the patient but to gather the important information that they would need before seeing the patient for the first time. The two patients were randomly selected from the repository of clinical records of 22,500 deceased patients FDA-approved Drug Library cell assay from the Royal Marsden Hospital in London. One (patient A) had a diagnosis of

breast cancer (breast carcinoma with bony metastases); her hospital records cover 32 consultations over four and a half years, and consist of 43 documents; the other (patient B) had a diagnosis of invasive ductal carcinoma, with records covering 8 consultations over one year and consisting of 11 documents (see Table 1 and Table 2). The records for each patient covers only the time they were treated at the Royal Marsden; patient A had received treatment elsewhere for five years prior and patient selleck chemicals llc B for one year. Although already anonymised by the hospital, the records were subject to further careful scrutiny by two experts

to remove all information that could identify the patient (e.g., occupation, consultant names, place names, etc.). Even so, all participants in our study were required to sign a non-disclosure agreement. The ten questions addressed issues that our clinical partners advised were key ones for a clinician about to see new cancer patient: • What is the presenting symptom/complaint? Each clinician was presented with a set of records for each patient. For one patient they were given the original hospital records (consisting of a collection of documents);

this mimicked the standard scenario for this website a doctor about to treat a new patient already diagnosed with cancer. For the other patient, they were given three summary records that were generated by the Report Generator: a full longitudinal summary, a summary from the perspective of clinical problems (e.g., cancer, anaemia or pain) and a summary from the perspective of curative procedures (e.g., chemotherapy, radiotherapy or surgery). Half of the subjects received the full records for Patient A and the summarised records for Patient B, and the other half received them the other way around. To avoid a biasing effect, half the subjects received the summaries before the full records, and the other half the other way around. All subjects received all questions in the same order. The clinicians read the records or summaries (in different sessions) and then answered the 10 questions. For each set, they were given 5 min for a ‘preliminary reading’ before proceeding to the questions.

These mutations cause a reduction in the overall levels of methylation on H3K27 by targeting the active site of SET-domain containing methyl transferases [45••]. The loss of H3K27 methylation is predicted

to disrupt a feedback loop that regulates the polycomb repressor complex 2 (PCR2), which then promotes the cancer state. Thus, histones can play a pivotal role selleck in the progression of the disease state, making them potential candidates to consider for therapeutic targeting. As is evident from the large body of literature on histones and their variants, nucleosomes and their structure, and chromatin organization in vitro and in vivo, this topic is a continuously evolving chapter in the study of genomes. Despite almost 40 years of steady progress on understanding chromatin, profound open questions persist that make this field one of the most exciting to investigate. Do histone variants have different preferences for particular DNA sequences?

Do histones re-associate with the same DNA sequence after being disrupted? Is there true molecular memory at sites that are to be marked for the next cell cycle? How is such memory over-ridden when cells embark on different developmental programs? How does the vigorous compression in the mitotic chromosome physically affect the position and stability of various types of nucleosomes? When cells age or transit into resting phase, how does the proportion of histone variants and nucleosome positions change, and how do such phenomena affect the rate of gene expression, DNA repair, GPX6 www.selleckchem.com/products/BIRB-796-(Doramapimod).html remodeling and replication? All these questions await answers, which will eventually bring a more complete conceptual framework of the behaviors

used to regulate genetic accessibility by these tiny, but crucial proteins, the tricksters of the genome. Papers of particular interest, published within the period of review, have been highlighted as: • of special interest “
“Current Opinion in Genetics & Development 2014, 25:15–21 This review comes from a themed issue on Genome architecture and expression Edited by Victor Corces and David L Levens For a complete overview see the Issue and the Editorial Available online 22nd December 2013 0959-437X/$ – see front matter, © 2013 The Authors. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.gde.2013.10.013 DNA is a dynamic molecule. In its relaxed state it adopts a right-handed helically coiled conformation, the detailed structure of which is dependent on the localised sequence. Winding DNA around its axis introduces supercoils increasing the free energy stored in the molecule; winding in the same direction as the helix introduces positive supercoiling whereas winding in the opposite direction generates negative supercoiling [1 and 2]. In addition to supercoiling derived from changes in DNA twist, it is also a product of the coiling or bending of the helix in space, a parameter commonly termed writhe.