Search

The present study examined how the use of soil color can help build and evaluate clay content prediction models from laboratory visible and near infrared spectroscopic data. This study was based on a regional database containing 449 soil samples collected over Karnataka state in India, which has been divided into red soils (240 samples) and black soils (209 samples) based on their Munsell soil color. Partial least squares regression models were calibrated and validated from both the regional datasets and subsets stratified as red and black soils. In addition, a random forest model was used to classify the validation soil samples into black and red classes to evaluate models’ performance. First, while the clay content predicted by the regression model built from regional data was evaluated as correct at regional scale (R2valof 0.75), this model was evaluated as more accurate over black (R2valof 0.8) than red (R2valof 0.63) soil samples. Second, the regression models built from subsets stratified per soil color provided different performances than the regression model built from the regional data, both at the regional scale and soil color scale. In conclusion, this study demonstrated that (1) predictions are highly dependent on calibration data, (2) the interpretation of prediction performances relies heavily on validation data, and (3) pedological knowledge, such as soil color, can be effectively employed as an encouraging covariate in both the construction and evaluation of regression models. Prediction of clay from visible and near infrared spectroscopy was analyzed based on soil color.Models were calibrated from regional database and subsets stratified by soil color.Globalmodel yielded over‐ and underestimation of accuracy over red and black soils, respectively.Predictions are highly dependent on the calibration dataset.Model performance evaluation is highly dependent on validation data stratification.

The aim of the work is to prepare and observe the metallographic specimen of 304L, 316L and 347 ASS samples with two different etching techniques. The samples were prepared by cutting, coarse grinding at 80 grit paper followed by fine grinding with 800, 1000, 1500, 2000 grit paper, polishing with diamond paste and kerosene on a velvet cloth. Later the samples were etched in aqua regia by immersion for 1 minute and in oxalic acid for electrolytic etching for 1 minute. The structure was observed at two different magnifications, 100× and 400×, using a light microscope. Electrolytic etching showed better results compared to the immersion technique. The structure was uniformly etched and had uniform light reflection. In addition to the clear structure, other particle phases were clearly visible. The 304L structure was fine grained as compared to 316L and 347 ASS. The structure observed was equiaxed austenite grains, annealed twins and particles.

One humped camel (Camelus dromedarius) breeds, indigenous to India, have been shown to have good genetic potential to produce milk. Camel milk not only is cost-effective in terms of feed conversion but also has additional advantage of longer lactation period and unique adaptation mechanisms for warm arid and semiarid regions. The key features of camel milk in comparison with other milk are low fat with high content of unsaturated and long-chain fatty acid. The proteins are rich in lactoferrin and lysozymes, but deficient in β-lactoglobulin. It has higher percentage of total salts, free calcium, protective proteins and vitamin C, and some of the microminerals, viz iron, copper and zinc. Physicochemical properties of camel milk are also unique and useful for food processing. The shelf life of raw camel milk is 8–9 h, which can be extended up to 18–20 h through activation of camel lactoperoxidase system. Heat stability of camel milk is shown to be highest at pH 6.8, and it ferments relatively slowly compared to the cattle milk. The camel milk is successfully processed for producing a variety of products, such as fermented milk (‘lassi’), soft cheese, flavored milk and ‘kulfee’ (a kind of ice cream). Camel milk has been traditionally used in different regions of the world as natural adjuvant for managing a variety of human diseases.

Selective laser melting SLM is an additive manufacturing AM process in which parts are fabricated by selectively melting regions of the surface of a metallic powder bed in a layer-by-layer fashion. Various thermal phenomena such as heat conduction, convection, radiation, melting and solidification, dynamic phase changes, and evaporation occur during the SLM process. In addition, laser intensity and powder bed scan speeds during processing complicate understanding of the process due to complex dynamic interactions between the powder bed and laser. In order to study these dynamic interactions, a finite element model has been developed which uses a dynamic mesh with spatial non-linear thermal properties to track the point of laser exposure on the powder bed to study thermal evolution during SLM. The model is able to achieve a refined, localised mesh in the melt zone and heat affected zone HAZ, surrounded by a relatively coarse mesh outside of the HAZ regions. The dynamic meshing for this implementation is achieved using both the sub-modelling functionality in ANSYS and a new set of algorithms being commercialised by 3DSIM, LLC. It was found that dynamic meshing reduces the model size and computational burden. In this paper, the use of the sub-modelling approach for dynamic meshing was verified by comparing it against a uniform fine mesh model. The results of the two models match within an acceptable tolerance. Also, a mesh sensitivity analysis was carried out in order to show solution convergence as a function of increasing mesh density. The results of this analysis were also validated using experiments to show a match between experimental and simulated melt pools. Finally, the ANSYS solution was compared with a new set of dynamic meshing finite element analysis algorithms running in Matlab. It was found that these new algorithms were significantly faster than their ANSYS counterparts for solving problems using a dynamic mesh.

The role of plasticity generated by quenched disorder in soft vortex matter is observed in both the plastic flow of vortices at low velocities and in plastic deformation in the pinned state. Some special experimental consequences of plasticity and the attendant metastability are summarized.

An extended cost study consisting of 14 process scenarios was carried out to envisage the cost impact of microprocessing and microwaves separately or in combination for two liquid-phase model reactions in fine-chemicals synthesis: (1) Ullmann C–O cross-coupling reaction and (2) the aspirin synthesis. The former, a Cu-catalyzed substitution reaction, was based on an experimental investigation, whereas the latter, a noncatalyzed aromatic esterification reaction, was based on literature data. The cost of 4-phenoxypyridine production, as a pharmaceutical intermediate in the synthesis of vancomycin or vancocin, was compared with that of the synthesis of aspirin, a key example of large-scale fine-chemical production plants. The operating costs in the Ullmann synthesis were found to be related to material-based process (reactant excess, pretreatment, and catalyst synthesis), whereas those in the aspirin synthesis appeared to be related to downstream-based process (workup, waste treatment). The impact of an integrated microwave heating and microprocessing system on profitability was demonstrated with respect to operational cost and chemical productivity. Different modes of microwave heating and catalyst supply were studied and compared with conventional oil-bath-heated systems in batch and continuous processes. The overall costs including profitability breakthrough for a competitive market price of product were obtained from various combinations of heating and processing. In case of the Ullmann synthesis, the CAPEX (capital expenditure) was negligible compared to the OPEX (operational expenditure), whereas in the aspirin synthesis, the CAPEX was found around 40%, both at a production scales of 1–10 kg/day using proposed upscale methods. The source of the catalyst strongly determined the profitability of a continuously operated Ullmann process due to its effect on the chemical performance. Higher energy efficiencies could be attained using single-mode microwave irradiation; however, the energy contribution to the overall cost was found to be negligible. Different scenarios provided a cost-feasible and profitable process; nevertheless, an integrated microwave heating and microflow processing led to a cost-efficient system using a micropacked-bed reactor in comparison to wall-coated microreactor, showing a profit margin of 20%.

Abstract: Background: Herniation of retroperitoneal adipose tissue into the inguinal canal, traditionally called cord lipoma, is frequently encountered during endoscopic totally extraperitoneal inguinal hernioplasty (TEP). Failure to recognize and manage the cord lipoma accounted for 30%–50% of recurrent hernia after TEP. The present study was undertaken to evaluate the incidence, risk factors, and management of herniated retroperitoneal adipose tissue during TEP. Methods: Between December 2002 and November 2005 all patients who underwent TEP were prospectively evaluated for the presence of cord lipoma. Clinical outcomes of patients who were treated for their cord lipoma were compared with those without cord lipoma. Risk factors for the occurrence of cord lipoma were also examined. Results: A total of 498 patients underwent unilateral (n = 386) or bilateral (n = 112) TEP. The overall incidence of cord lipoma was 26.5% (n = 132). A higher body weight, a higher body mass index, and a larger hernial defect were significantly associated with the presence of cord lipoma. Most of the cord lipoma cases (n = 119) were reduced to pelvic peritoneal reflection line after division of the feeding vessels from surrounding structures, while the rest (n = 13) were resected. Early postoperative outcomes, including pain score, morbidities, and other recovery variables, showed no significant difference between the two groups. No recurrence occurred in the present series. Conclusions: Herniation of retroperitoneal adipose tissue into the inguinal canal occurred in more than one-fifth of the patients with inguinal hernia. Awareness and appropriate treatment of the cord lipoma helped to reduce the risk of recurrence. During TEP, the internal inguinal ring and inguinal canal should always be cleared of any herniated adipose tissue by either reduction or resection. This clearing posed no adverse effects on postoperative outcome.

Background: Endoscopic totally extraperitoneal inguinal hernioplasty (TEP) is an accepted technique for the repair of recurrent and bilateral inguinal hernia, but its role in the management of unilateral primary inguinal hernia remains controversial. The current randomized trial was undertaken to compare the postoperative and 1-year outcomes of day-case TEP and open Lichtenstein hernioplasty for unilateral primary inguinal hernia in males. Methods: From January 2002 to January 2004, a total of 200 male patients were randomized to undergo either day-case unilateral TEP or open Lichtenstein hernioplasty under general anesthesia. The primary outcome measures included postoperative pain score, time until return to work, incidence of chronic groin pain, and recurrence rate 1 year after the operation. Results: All TEP procedures were successfully performed without conversion. The mean operation time for TEP (50±13.2 min) was significantly shorter than for open Lichtenstein hernioplasty (58 ± 17.6 min) (p< 0.001). The pain score at rest was significantly lower in the TEP group than in the open group on postoperative days 0, 1, 4, 5, and 6. On the average, the patients returned to work 8.6 days after TEP and 14 days after Lichtenstein hernioplasty (p= 0.006). Postoperative recovery and morbidity rates were otherwise comparable between the two groups. The incidence of chronic groin pain 1 year after TEP (9.9%) was significantly lower than after open surgery (21.7%) (p= 0.032). None of the patients in either group showed recurrence at the last follow-up assessment. Conclusions: Day-case TEP was superior to open Lichtenstein hernioplasty for the repair of unilateral primary inguinal hernia in males. The benefits of day-case TEP included less postoperative pain, a faster return to work, and a lower incidence of chronic groin pain.

Background: Early laparoscopic cholecystectomy has been advocated for the management of acute cholecystitis, but little evidence exists to support the superiority of this approach over delayed-interval operation. The current systematic review was undertaken to compare the outcomes and efficacy between early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis in an evidence-based approach using metaanalytical techniques. Methods: A search of electronic databases, including MEDLINE and EMBASE, was conducted to identify relevant articles published between January 1988 and June 2004. Only randomized or quasi-randomized prospective clinical trials in the English language comparing the outcomes of early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis were recruited. Both qualitative and quantitative statistical analyses were performed. The effect size of outcome parameters was estimated by odds ratio or weighted mean difference where feasible and appropriate. Results: A total of four clinical trials comprising 504 patients met the inclusion criteria. Failure of conservative treatment requiring emergency cholecystectomy occurred for 43 patients (23%) in the delayed group. Metaanalyses demonstrated a significantly shortened total length of hospital stay in the early group (weighted mean difference, −1.12; 95% confidence interval [CI], −1.42 to −0.99; p< 0.001). Pooled estimates did not show any significant differences between the two approaches in terms of operation time, conversion rate, overall complication rate, incidence of bile leakage, and intraabdominal collection. Conclusions: The safety and efficacy of early and delayed-interval laparoscopic cholecystectomy for acute cholecystitis were comparable. Because evidence suggested that early laparoscopic cholecystectomy reduced the total length of hospital stay and the risk of readmissions attributable to recurrent acute cholecystitis, it is therefore a more cost-effective approach for the management of acute cholecystitis.

Abstract: Background: Groin hernia is an uncommon surgical pathology in females. The efficacy of the endoscopic approach for the repair of female groin hernia has yet to be examined. The current study was undertaken to compare the clinical outcomes of female patients who underwent open and endoscopic totally extraperitoneal inguinal or femoral hernioplasty (TEP). Methods: From July 1998 to June 2004, 108 female patients who underwent elective repair of groin hernia were recruited. The patients were divided into TEP (n = 30) and open groups (n = 78) based on the type of operation. Clinical data and outcome parameters were compared between the two groups. Results: The mean ages and hernia types were comparable between the two groups. All TEPs were successfully performed. The mean operative times were 52 min for unilateral TEP and 51 min for open repair. The difference was not statistically significant. Comparisons of the length of hospital stay, postoperative morbidity, pain score, and time taken to resume normal activities showed no significant differences between the two groups. A single patient in the TEP group experienced recurrence of hernia. Conclusions: The findings show equivalent postoperative outcomes after TEP and open repair of groin hernia in female patients. Because the wound scar after open repair is well concealed beneath the pubic hair and no superior clinical benefits are observed after TEP, open repair appears to be the technique of choice for the management of primary groin hernia in females. The TEP approach should be reserved for female patients with recurrent or multiple groin hernia.

Synthesis of crosslinked chitosan using γ irradiation in the presence of carbon tetrachloride as a sensitizer is carried out. The resultant crosslinked product, which is yellow in color, is characterized by elemental analysis, which shows the presence of chlorine. Crosslinked chitosan on hydrolysis with alkali results in the formation of another product that retains the crosslinked structure but does not have chlorine in it. Gel formatting characteristics of both these products have been studied. The crosslinked chitosan and its hydrolysis product are further characterized by various physical methods such as X‐ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and thermogravimetry. Based on the results, a probable mechanism of crosslinking whereby chitosan chains are crosslinked by a >CCl2 group is suggested. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3897–3909, 2004

It is found that the nucleation of domains can take place in Ba5Ti2O7Cl4under the influence of temperature unlike in many other ferroelectrics. The nucleated domain can also be removed from the structure under the randomizing effect of temperature. These observations have been explained on the basis of a nucleation model of Ingle and coworkers suggested for KNbO3. Similarity of physical situation in KNbO3and Ba5Ti2O7Cl4regarding the existence of ordered point defects inducing nucleation of domains around them has been highlighted. This surprising similarity is suggested to be due to the physical processes occurring at the phase transition rather than due to any structural resemblance. The nature of nucleation occurring under the influence of temperature is shown to be identical with the nature of nucleation occurring under the influence of externally applied stress, and/or DC electric field. A new technique of identifying point defects responsible for nucleation of domains is reported.

Background: Pain is the most common complaint after inguinal hernia surgery. The present study was undertaken to evaluate the significance of various perioperative clinical factors on the severity of postoperative pain following endoscopic totally extraperitoneal (TEP) inguinal hernioplasty. Methods: Between November 1999 and December 2002, 509 patients who underwent unilateral ( n = 389) and bilateral ( n = 120) TEP were recruited for this study. There were 491 men and 18 women. Severity of postoperative pain at rest and on coughing was assessed by a linear analogue pain score (scale, 0–10) on a daily basis after operation. Univariate and multivariate analyses were performed to identify the significant independent factors affecting pain. Results: By univariate analysis, pain scores at rest were significantly higher in young (≤65 years) female patients, as well as patients who underwent unilateral and day case TEP. Clinical factors associated with a significantly higher pain score on coughing included mesh fixation by stapling, female sex, and age (≤65 years). Other factors, including unilateral vs bilateral TEP, seroma formation, direct vs indirect hernia, primary vs recurrent hernia, and operative time, had no impact on postoperative pain. On multiple regression analysis, age and sex were found to be independent predictive factors for mean daily pain score at rest. Independent factors influencing mean pain score on coughing included age, sex, and prosthetic stapling. Conclusions: Patient age and sex are the most significant factors determining the degree of pain after TEP. Analgesic therapy should therefore be adjusted in accordance with the age of the patient. With regard to operative factors, avoidance of prosthetic stapling might help to reduce the severity of pain on coughing.

Background: There is no consensus on the best technique for the repair of umbilical hernia in adults. The role of laparoscopic hernioplasty of umbilical hernia remains controversial. This study was undertaken to compare the outcomes of open and laparoscopic onlay patch repair of umbilical hernia in adults. Methods: From January 1996 to December 2002, 102 patients underwent elective repair of umbilical hernia. Operative techniques included Mayo repair ( n = 43), laparoscopic onlay Gore-Tex patch hernioplasty ( n = 26), suture herniorrhaphy ( n = 24), and mesh hernioplasty ( n = 9). Results: Demographic features and risk factors were similar among the four groups. The operative time of laparoscopic hernioplasty (median, 66 min) was significantly longer than those for patients who underwent Mayo repair (60 min) or sutured herniorrhaphy (50 min) ( p < 0.05). None of the patients who underwent laparoscopic patch repairs required conversion to open repair. The median pain score at rest on postoperative day 1 was significantly lower in patients who underwent laparoscopic repair compared to those who had Mayo repair. A significantly shorter hospital stay and a lower wound morbidity rate were also observed in patients who underwent laparoscopic repair. With a mean follow-up of 2 years, suture herniorrhaphy had a relatively high recurrence rate (8.7%), whereas no recurrence was documented for the other techniques. Conclusions: Laparoscopic onlay patch hernioplasty is a safe and efficacious technique for the repair of umbilical hernia. Compared to Mayo repair, the laparoscopic approach confers the advantages of reduced postoperative pain, shorter hospital stay, and a diminished morbidity rate.

Background: Chronic groin pain after open inguinal hernia repair is a common long-term morbidity, but its incidence after endoscopic totally extraperitoneal inguinal hernioplasty (TEP) has not been studied in detail. The objective of this study was to evaluate the prevalence and severity of chronic groin pain after TEP. Methods: Between June 1999 and September 2001, 313 consecutive patients who underwent TEP at our institution were recruited. To evaluate the incidence and severity of chronic pain, a cross-sectional telephone survey using a standardized questionnaire was conducted by a research assistant. Clinical data between the chronic pain group and the pain-free group were compared to identify any clinical factors that had a significant association with the subsequent development of chronic groin pain. Results: The prevalence of chronic groin pain was 9.2% ( n = 24). The severity of the pain was mild ( n = 18), moderate ( n = 5), or severe ( n = 1). In more than half of the patients, the groin pain occurred less often than once a month and its duration did not exceed 1 min. Only one patient reported an impairment of functional activities as a result of the pain. Multivariate analyses identified a significant association between a high postoperative pain score on coughing on postoperative day 6 and the subsequent development of groin pain. Conclusions: The prevalence of chronic groin pain in patients after TEP was low. The pain was mostly mild and transient without associated sensory symptoms. The occurrence of pain had a negligible impact on daily activities.

Domain structures in the new ferroelectric Ba 5 Ti 2 O 7 Cl 4 have been analysed with the help of metallurgical and polarizing microscope. The results are shown to agree with the crystal structure reported by the authors earlier and with the group theoretical analysis. X-ray diffraction results have been used to obtain the displacement of the off-center Cl 1 m ion, and it is shown that these results are in agreement with the results obtained by optical method considering the two alternate positions for the domain walls passing through the Cl 1 m ion. The crystal is shown to possess 180°, 90° and 79° domains with twinning respectively on (011) [also (101)], (110) [also (1 ¥ 10)] and (021) [also (201)] planes. The view of domain lines is identical on (100) and (010) planes as expected from the crystal structure. For 180° and 90° domains, the polar axis can lie in - a or - b directions, and for 79° domains, in - d 110 ¢ or - d 1 ¥ 10 ¢ directions. Thus, the crystal is a two dimensional ferroelectric. On account of large difference between the a (or b ) and c lattice parameters, the polar axis does not change its direction from a (or b ) to c . Rather large size of the unit cell is shown to be associated with large displacement of the Cl 1 m ion (about 0.18 Å). The 79° domains are shown to be associated with displacement of Ti 4+ ions, and 180° and 90° domains with displacement of Cl 1 m ions. This gives that Ti 4+ ion is displaced in d 110 ¢ direction.

Comparison of human sequences with the DNA of other mammals is an excellent means of identifying functional elements in the human genome. Here we describe the utility of high-density oligonucleotide arrays as a rapid approach for comparing human sequences with the DNA of multiple species whose sequences are not presently available. High-density arrays representing approximately 22.5 Mb of nonrepetitive human chromosome 21 sequence were synthesized and then hybridized with mouse and dog DNA to identify sequences conserved between humans and mice (human-mouse elements) and between humans and dogs (human-dog elements). Our data show that sequence comparison of multiple species provides a powerful empiric method for identifying actively conserved elements in the human genome. A large fraction of these evolutionarily conserved elements are present in regions on chromosome 21 that do not encode known genes.

Elevated plasma lipoprotein levels play a crucial role in the development of coronary artery disease. Genetic factors strongly influence the levels of plasma lipoproteins, but the genes and sequence variations contributing to the most common forms of dyslipidemias are not known. We used GeneChip probe arrays to resequence the coding regions of 10 key genes of lipid metabolism. The sequences of these genes were analyzed in 80 dyslipidemic individuals. Fourteen nonsynonymous and twenty-two synonymous single nucleotide changes were identified that could be confirmed by conventional sequencing. Seven of the fourteen nonsynonymous sequence variants were polymorphisms with allele frequency >1% in the general population. The remaining seven were not found in normolipidemic controls (25 Caucasians and 25 African-Americans). The relationship between nonsynonymous sequence variations and various dyslipidemias was explored in association and family studies. No evidence was found for coding sequence variations in any of the 10 genes contributing to dyslipidemia. Only a single sequence variation, a missense mutation in the low density lipoprotein receptor gene, co-segregated with hyperlipidemia in the proband's family. This study illustrates some of the difficulties associated with identifying sequence variations contributing to complex traits.

Most human cancers are characterized by genomic instability, the accumulation of multiple genetic alterations and allelic imbalance throughout the genome. Loss of heterozygosity (LOH) is a common form of allelic imbalance and the detection of LOH has been used to identify genomic regions that harbor tumor suppressor genes and to characterize tumor stages and progression. Here we describe the use of high-density oligonucleotide arrays for genome-wide scans for LOH and allelic imbalance in human tumors. The arrays contain redundant sets of probes for 600 genetic loci that are distributed across all human chromosomes. The arrays were used to detect allelic imbalance in two types of human tumors, and a subset of the results was confirmed using conventional gel-based methods. We also tested the ability to study heterogeneous cell populations and found that allelic imbalance can be detected in the presence of a substantial background of normal cells. The detection of LOH and other chromosomal changes using large numbers of single nucleotide polymorphism (SNP) markers should enable identification of patterns of allelic imbalance with potential prognostic and diagnostic utility.

No Abstract.

Approximately 6000 specific DNA deletion events occur during development of the somatic macro-nucleus of the ciliate Tetrahymena. The eliminated Tlr1 element is 13 kb or more in length and has an 825 bp inverted repeat near the rearrangement junctions. A functional analysis of the cis -acting sequences required for Tlr1 rearrangement was performed. A construct consisting of the entire inverted repeat and several hundred base pairs of flanking DNA on each side was rearranged accurately in vivo and displayed junctional variability similar to the chromosomal Tlr1 rearrangement. Thus, 11 kb or more of internal element DNA is not required in cis for DNA rearrangement. A second construct with only 51 bp of Tetra-hymena DNA flanking the right junction underwent aberrant rearrangement. Thus, a signal for determination of the Tlr1 junction is located in the flanking DNA, 51 bp or more from the right junction. Within the Tlr1 inverted repeat are 19 bp tandem repeats. A construct with the 19mer repeat region deleted from the right half of the inverted repeat utilized normal rearrangement junctions. Thus, despite its transposon-like structure, Tlr1 is similar to other DNA rearrangements in Tetrahymena in possessing cis -acting sequences outside the deleted DNA.

Ever since Bárány &Wittmaack (1) studied the effects of stimulating the vestibular system, the quantification and clinical significance of experimentally induced nystagmus has been a subject of constant debate. The fallacy of most suprathreshold investigations in current use (caloric, positional, accelerative and rotational stimulation tests, for example) is that they do not lend themselves easily to standardization and topodiagnosis. Various authors (Bárány, Grahe, Bákásy, Hozawa, Wolf, Rubin, etc.) have described different rotatory protocols using short/forced turning, supra, subliminal or pendular rotation and acceleration/deceleration, either singly or in combination. The stimulus is based on Ewald's principle, which maintains that perrotatory nystagmus is elicited by stimulating the ear in the direction of turning, while the contralateral ear is responsible for postrota-tory nystagmus. The rotational intensity damping test (RIDT) employed by our group for over a decade attempts to overcome these problems by combining a supraliminal step-like perrotatory stimulus with a supramaximal needle-shaped postrotatory stimulus in a trapezoidal pattern, and by setting normal ranges for these protocols. The result may then be jointly represented using an "chart".

A set of 1 021 patients who were investigated at our Department over the last few years was investigated in this study. Each patient underwent Cranio-Corpo-Graphy, and other related investigations. The patients' CCG's were quantified using a specially developed computer scanning method, and a computerized spreadsheet databank was thus created. Also included in the study were their clinical profiles, as charted using the NODEC I I I questionnaire. The isolation and comparison of various data subsets enables us to draw broad correlations between clinical and CCG findings, and permits us to establish 'normal values' for various parameters. It is seen that cranio-corpography is a reliable screening method for the topodiagnosis of vertigo.

Tris(2-ethylhexyl)phosphate is proposed as an extractant for the solvent extraction of zinc and copper salicylate. The optimum extraction conditions are established by studying the various experimental parameters such as pH, sodium salicylate concentration, tris(2-ethylhexyl)phosphate concentration, equilibration period, and various diluents. The probable extracted species as ascertained by log D-log C plots is Zn(HSal)22T2EHP and Cu(HSal)22T2EHP. The method permits mutual separation of zinc and copper and can be used for separation and determination of zinc and copper in environmental and pharmaceutical samples.

Expression of nerve growth factor receptor is normally restricted to cells derived from the neural crest in a developmentally regulated manner. We analyzed promoter sequences for the human nerve growth factor receptor gene and found that the receptor promoter resembles others which are associated with constitutively expressed genes that have housekeeping and growth-related functions. Unlike these other genes, the initiation of transcription occurred at one major site rather than at multiple sites. The constitutive nature of the nerve growth factor receptor promoter may account for the ability of this gene to be transcribed in a diverse number of heterologous cells after gene transfer. The intron-exon structure of the receptor gene indicated that structural features are precisely divided into discrete domains.

The studies on temperature autostabilized nonlinear dielectric element (TANDEL) effect and second harmonic generation (SHG) for ferroelectric LiVO3 doped with Gd2O3 (0.025 to 3 mol %) in the vicinity of Curie temperature indicate that the generated second harmonic is linear for low d.c. biasing fields with a zero off-set. Deviations from linear behavior and a sharp decrease in the amplitude of second harmonic are observed at higher d.c. biasing fields. The zero off-set might be due to the presence of defects, giving rise to an internal bias which, in turn, generates a second harmonic. The amplitude of generated second harmonic and the zero off-set increase for 0.025, 0.05 and 0.1 mol % whereas decrease for 1 and 3 mol % of Gd2O3, with respect to LiVO3.