Development of near homozygous lines for diploid hybrid TPS breeding in potatoes.

Diploid inbred-based F1 hybrid True Potato Seed (DHTPS) breeding is a novel technique to transform potato breeding and cultivation across the globe. Significant efforts are being made to identify elite diploids, dihaploids and develop diploid inbred lines for heterosis exploitation in potatoes. Self-incompatibility is the first obstacle for developing inbred lines in diploid potatoes, which necessitates the introgression of a dominant S locus inhibitor gene (Sli) for switching self-incompatibility to self-compatibility. We evaluated a set of 357 diploid clones in different selfing generations for self-compatibility and degree of homozygosity using Kompetitive Allele Specific PCR (KASP) Single Nucleotide Polymorphism (SNP) markers. A subset of 10 KASP markers of the Sli candidate region on chromosome 12 showed an association with the phenotype for self-compatibility. The results revealed that the selected 10 KASP markers for the Sli gene genotype could be deployed for high throughput rapid screening of self-compatibility in diploid populations and to identify new sources of self-compatibility. The homozygosity assessed through 99 KASP markers distributed across all the chromosomes of the potato genome was 20-78 % in founder diploid clones, while different selfing generations, i.e., S0, S1, S2 and S3 observed 36.1-80.4, 56.9-82.8, 59.5-85.4 and 73.7-87.8 % average homozygosity, respectively. The diploid plants with ∼80 % homozygosity were also observed in the first selfing generation, which inferred that homozygosity assessment in the early generations itself could identify the best plants with high homozygosity to speed up the generation of diploid inbred lines.

Physiological and biochemical response in green mussel Perna viridis subjected to continuous chlorination: Perspective on cooling water discharge criteria.

Heavy infestation by Perna viridis has been observed in the sub-seabed seawater intake tunnel and CWS of a tropical coastal power station in-spite of continuous low dose chlorination regime (0.2 ± 0.1 mg L-1) (CLDC), indicating periodical settlement and growth. Continuous arrival of mussels (colonized in the sub seabed tunnel intake section) at the pump house indicated that the mussels were able to tolerate and survive in a chlorinated environment, for varying time periods and were dislodged when they become weak and subsequent death, leading to flushing out of the system. In the present study, effect of continuous chlorination [0.2 mg L-1 (in-plant use); 0.5 mg L-1 (shock dose) & 1.0 mg L-1 (high levels)] was evaluated on mussels to assess; (a) time taken for mortality, (b) action of chlorine on physiological, genetic, metabolic and neuronal processes. 100% mortality of mussels was observed after 15 (0.2 mg L-1); 9 (0.5 mg L-1) and 6 days (1.0 mg L-1) respectively. Extended valve closure due to chlorination resulted in stress, impairing the respiratory and feeding behavior leading to deterioration in mussel health. Pseudofaeces excretion reduced to 68% (0.2 mg L-1); 10% (0.5 mg L-1) and 89% (1.0 mg L-1) compared to controls. Genotoxicity was observed with increase in % tail DNA fraction in all treatments such as 86% (0.2 mg L-1); 76% (0.5 mg L-1) and 85% (1.0 mg L-1). Reactive Oxygen Species (ROS) stress biomarkers increased drastically/peaked within the first 3 days of continuous chlorination with subsequent quenching by antioxidant enzymes. Gill produced highest generation of ROS; 38% (0.2 mg L-1); 97% (0.5 mg L-1); 98% (1.0 mg L-1). Additionally, it was shown that 84% (0.2 mg L-1), 72% (0.5 mg L-1), and 80.4% (1.0 mg L-1) of the neurotransmitter acetylcholinesterase activity was inhibited by chlorine at the nerve synapse. The cumulative impact of ROS generation, neuronal toxicity, and disrupted functions weakens the overall health of green mussels resulting in mortality.

A Prospective Comparative Study of Laparoscopic Totally Extraperitoneal (TEP) and Laparoscopic Transabdominal Preperitoneal (TAPP) Inguinal Hernial Repair.

Introduction Inguinal hernia is a common surgical problem throughout the world. Currently, the management options available are open mesh hernioplasty and laparoscopic mesh repair. Laparoscopic mesh repair can be performed by either transabdominal preperitoneal (TAPP) repair or totally extraperitoneal (TEP) repair. Many studies comparing the two procedures have been unable to establish the superiority of one procedure over the other and have yielded conflicting results. Thus, we performed this study to compare TAPP and TEP. Aim The aim of this study is to compare the clinical outcomes and safety of laparoscopic TEP and laparoscopic TAPP for inguinal hernia repair. Materials and methods Patients were randomly divided into two groups on the basis of surgical procedures. The first group of patients underwent laparoscopic TAPP mesh repair, and the second group of patients underwent laparoscopic TEP mesh repair. Their intraoperative and postoperative findings were noted. Patients were followed up at regular intervals for up to six months. Results The mean age and mean weight distribution between the two groups were not significant. The duration of surgery needed (in minutes) for TAPP was found to be significantly less compared to TEP. In the TEP group, conversion to open occurred for three subjects (6.7%) while there was no conversion in the TAPP group. Postoperative pain at 24 hrs was found to be higher in TAPP subjects compared to that in TEP subjects, but the difference was statistically insignificant. Tolerance to a liquid diet started few hours after surgery was found to be the same in both groups. Association of the duration of hospital stays with the type of surgery was not significant. Six subjects (13.2%) showed hematoma in the TEP group while five subjects (11%) in the TAPP group showed hematoma after one week of surgery. Eight subjects (17.6%) showed seroma in the TEP group while three subjects (15.4%) in the TAPP group showed seroma after one week of surgery. Two subjects (4.4%) showed superficial wound infection in both the TEP group and TAPP group after one week of surgery. Four subjects each (8.9%) showed scrotal edema in the TEP group as well as the TAPP group after one week of surgery. No subject showed port site hernia without closure of the sheath at one-week, one-month, and six-month follow-up visits. Two subjects (4.4%) each showed groin pain in the TEP group as well as the TAPP group after one week of surgery. There were no instances of bowel obstruction or mesh infection. Conclusion TEP is a more skill-demanding procedure as compared to TAPP and thus takes more time to perform. However, it is superior on account of not breaching the peritoneum. TAPP is favorable for larger hernias. The choice of procedure should be individualized according to the patient's characteristics and surgeon's preference.

Digitalization of potato breeding program: Improving data collection and management.

A plant breeding program involves hundreds of experiments, each having number of entries, genealogy information, linked experimental design, lists of treatments, observed traits, and data analysis. The traditional method of arranging breeding program information and data recording and maintenance is not centralized and is always scattered in different file systems which is inconvenient for retrieving breeding information resulting in poor data management and the loss of crucial data. Data administration requires a significant amount of manpower and resources to maintain nurseries, trials, germplasm lines, and pedigree records. Further, data transcription in scattered spreadsheets and files leads to nomenclature and typing mistakes, which affects data analysis and selection decisions in breeding programs. The accurate data recording and management tools could improve the efficiency of breeding programs. Recent interventions in data management using computer-based breeding databases and informatics applications and tools have made the breeder's life easier. Because of its digital nature, the data obtained is improved even further, allowing for the acquisition of images, voice recording and other specific data kinds. Public breeding programs are far behind the industry in the use of data management tools and softwares. In this article, we have compiled the information on available data recording tools and breeding data management softwares with major emphasis on potato breeding data management.

Evaluation for substitution of stem bark with small branches of Myrica esculenta for medicinal use - A comparative phytochemical study.

BACKGROUND: Over exploitation of many traditional medicinal plants like Myrica esculenta has become a threat and in the near future, many medicinal plants may be unavailable for use of industry. OBJECTIVE: Present study outlines the concept of plant part substitution. Stem bark and small branches of M. esculenta are compared on the basis of physicochemical analysis, phytochemical analysis, total phenolic contents, total flavonoid contents and high performance thin layer chromatography (HPTLC) to evaluate the possibilities of using small branches in place of stem bark. MATERIAL AND METHODS: Physicochemical parameters and preliminary phytochemical screening were carried out using standard methods. Total phenolic and total flavonoid contents were estimated spectrophotometrically using Folin-Ciocalteu and aluminum chloride method, respectively. CAMAG HPTLC system equipped with semi-automatic applicator was used for HPTLC profiling. n-Hexane, ethyl acetate and ethanol extracts of stem bark and small branches were developed in suitable mobile phase using standard procedures and visualized in UV 254 and 366 nm and in white light after derivatization within anisaldehyde-sulphuric acid reagent. RESULTS: Phytochemical analysis and HPTLC profile of different extracts showed the presence of almost similar phytochemicals in both stem bark and small branches. CONCLUSION: Similarities in phytochemical analysis and HPTLC profile of various extracts suggests that small branches may be used in place of stem bark. The study provides the base for further study to use small branches as a substitute of stem bark of M. esculenta.

Single Incision Laparoscopic Assisted Appendectomy: Experience of 82 Cases.

INTRODUCTION: Single Incision Laparoscopic Surgery (SILS) is one of the most recent developments which have been made in the field of minimal assesses surgery. It has potential advantages of less postoperative pain and better cosmesis, but at the same time, this procedure is time consuming and it increases the cost of surgery. AIM: In this study, we evaluated the feasibility, safety and potential advantages of single incision laparoscopic assisted appendectomy. MATERIALS AND METHODS: Single incision laparoscopic assisted appendectomy was done in 82 patients who were diagnosed with acute or chronic appendicitis. A single 10mm incision made over right lower quadrant was used for placing two 5mm trocars and appendisectomy was done as in open surgery, after delivering out the appendix from the incision. RESULTS: Mean operative time was 32.56 ± 15.5 minutes. Mean post-operative pain scores as per visual analogue scalewere 6.5, 4.2 and 1.2 on 12 hours day 1 and day 2 after surgery respectively. Mean length of hospital stay was 1.4 ± 1.2 days. CONCLUSION: Single incision laparoscopic appendectomy is safe and feasible.

Plasma progesterone profile and conception rate following exogenous supplementation of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone releasing intra-vaginal device in repeat-breeder crossbred cows.

AIM: This study was designed to evaluate the effect of gonadotropin-releasing hormone (GnRH), human chorionic gonadotropin (hCG), and progesterone impregnated intra-vaginal device on progesterone profile and conception rate in repeat-breeding crossbred cows. MATERIALS AND METHODS: Repeat-breeding crossbred cows aged 3-8 years (n=32), lactating and negative to white side test were randomly divided into four groups: Group 1 (Control, n=8), Group 2 (GnRH at 10 µg i.m, n=8), Group 3 (hCG at 1500 IU i.m., n=8), and Group 4 (progesterone impregnated intra-vaginal device at 958 mg, n=8). All the treatme nts were given on 5(th) daypostbreeding and in Group 4 intra-vaginally implanted device was withdrawn on 9(th) day (i.e., implant inserted for total 4 days) of the estrous cycle. Blood samples were collected on day 0, 5, 10, 15, and day 20 of estrous cycle, and plasma was separated for progesterone estimation. RESULTS: Accessory corpus luteum was not formed in crossbred cows of Group4 and control group. However, total 6 and 8 accessory corpora lutea were found in Group 2 and Group 3, respectively. In pregnant cows, the plasma progesterone concentration increased continuously from day 0 to day 20. In non-pregnant cows, it increased from day 0 to day 15 and then declined. The conception rate on day 60 in Group 1, Group 2, Group 3, and Group 4 was 37.5%, 50%, 75%, and 37.5%, respectively. CONCLUSIONS: Treating repeat-breeder cows with hCG is effective in increasing conception rate by developing accessory corpora lutea and higher progesterone level.

Sexual maturation, serum steroid concentrations, and mRNA expression of IGF-1, luteinizing and progesterone hormone receptors and survivin gene in Japanese quail hens.

In avian species, sexual maturation represents the evidence of start laying, which is a consequence of the development of ovarian follicles. These follicles are the functional reproductive unit whose maturation and viability critically depends on endocrine, paracrine, and autocrine factors beyond the signals from the central nervous system. The present study was undertaken to investigate the correlation of sexual maturity with tissue growth, mRNA expression of certain genes, and serum steroid concentrations in Japanese quail hens. To carry out the present study, a total of forty Japanese quail hens (5 weeks) were housed individually under uniform husbandry condition with ad libitum quail layer ration and water at 14-hour photo schedule. On sixth week onwards, four birds were sacrificed at each time on 1, 3, 7, 10, 13, 16, 19, 22, 25, and 28 days. Serum was extracted aseptically to analyze the gonadal steroid hormones (estrogen and progesterone) and corticosterone to investigate the liaison with sexual maturation of the species. Expression analyses of four genes i.e., insulin-like growth factor-1, luteinizing hormone receptor, progesterone receptor, and survivin were carried out in the three largest ovarian yellow follicles. A significant (P < 0.05) increase in body weight gain and oviduct weight was recorded during the phase of sexual maturation. Smaller follicles revealed higher insulin-like growth factor-1 and survivin gene expression, whereas the reverse result was manifested in both the luteinizing and progesterone hormone receptors. In biochemical study, the gonadal steroids (estrogen and progesterone) were recorded higher at the first half of the experiment when a gradual decrease in corticosterone concentration was confirmed from the very beginning of this study. This result substantiated that sexual maturation in Japanese quail may be completed by the time of 8 weeks after its birth in support of the analyzed information studied in the current investigation.

Spectrophotometric determination of trace amounts of phosphate in water and soil.

A simple spectrophotometric method has been developed for the determination of phosphate dissolved in soil and water. The method is based on the formation of phosphomolybdate with added ammonium molybdate followed by reduction with hydrazine in acidic medium. Orthophosphate and molybdate ions condense in acidic solution to give molybdophosphoric (phosphomolybdic) acid, which upon selective reduction (perhaps with hydrazinium sulphate) produces a blue colour, due to molybdenum blue of uncertain composition. The intensity of blue colour is proportional to the amount of phosphate. If the acidity at the time of reduction is 0.5 M in sulphuric acid and hydrazinium sulphate is the reductant, the resulting blue complex exhibits maximum absorption at 830 nm. The system obeys Lambert-Beer's law at 830 nm in the concentration range of 0.5-5 µg/mL of phosphate with a relative standard deviation (RSD) of 0.1% and correlation coefficient of 0.99. Molar absorptivity was determined to be 2.9 × 104 L mol⁻¹ cm⁻¹ at 830 nm. The method is also applicable for the determination of phosphate in nuclear reprocessing plants, medical science, clinical science, agriculture, metallurgy and environmental science.

The role of the male cloacal gland in reproductive success in Japanese quail (Coturnix japonica).

The adult male Japanese quail has a well developed cloacal gland that produces meringue-like white foam. The physiological significance of the cloacal gland and its foam is still unclear. Therefore, we conducted two experiments to establish the functional role of the cloacal gland and its foam in natural mating and oviducal sperm transport. In the first experiment, artificial insemination of equal numbers of spermatozoa diluted in foam extract and normal saline once in a week were used to determine the role of foam in sperm transport in the female oviduct. After artificial insemination, eggs were collected to measure fertility, the duration of the fertile period, sperm holes and attached spermatozoa in the perivitelline membrane. Higher (P<0.05) fertility and greater duration of the fertile period were observed when semen was inseminated along with foam extract compared with normal saline. Further, the sperm holes and trapped spermatozoa in the perivitelline membrane were also higher (P<0.05) in the presence of foam extract. In the second experiment, two males with bigger and smaller cloacal gland areas were allowed to mate with a female. The mating attempts of males with larger cloacal gland were more successful (P<0.05) than males with smaller cloacal glands. Our results indicated that cloacal foam improves sperm transport in the female oviduct and that males with larger cloacal gland areas are preferred during mating.

Effect of Dietary L-ascorbic Acid (L-AA) on Production Performance, Egg Quality Traits and Fertility in Japanese Quail (Coturnix japonica) at Low Ambient Temperature.

Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks) were equally divided into three groups (20/group) based on the different dietary levels of L-AA (0, 250 and 500 ppm) and coupled with an equal number of males (1:1) obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05) in the present study. Fertility was improved significantly (p<0.01) to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail.

Cytokines Expression and Nitric Oxide Production under Induced Infection to Salmonella Typhimurium in Chicken Lines Divergently Selected for Cutaneous Hypersensitivity.

In the present study, the impact of Salmonella Typhimurium on cell-mediated immunity (CMI) was investigated in 5 week-old immuno divergent broiler lines selected for the high and low response to phytohemagglutinin-P. The immune response was assessed in peripheral-blood mononuclear cells (PBMCs) induced with Salmonella Typhimurium at different time intervals (0 h, 0.5 h, 2 h, 4 h, 6 h, 12 h and 24 h). The differential mRNA expression patterns of IFN-γ, IL-2 and iNOS were evaluated by quantitative real time PCR. In-vitro production of nitric oxide (NO) was also estimated in the culture supernatant and correlated with iNOS mRNA expression. Present study showed higher production of NO in the high cell-mediated line (HCMI) as compared to the low cell-mediated line (LCMI) upon stimulation with Salmonella Typhimurium. Correspondingly, higher mRNA expression of iNOS and IFN-γ were observed in high response birds (HCMI); but IL-2 was down regulated in this line compared to the low response birds (LCMI). Significantly (p<0.05) higher expression of iNOS, IFN-γ and higher production of NO in high line indicated that the selection for PHA-P response might be employed for increasing the immune competence against Salmonella Typhimurium in chicken flocks.

Synthesis and characterization of WO3 nanomaterials.

This work reports a simple, quick and economical method to prepare WO3 nanomaterials. Prepared tungsten trioxide materials have been sintered at 700 degrees C for three hours. The material has been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Crystallite size of the WO3 nanostructures obtained by Shearer's formula are between 12 and 72 nm and their grain size by SEM are from 20 to 105 nm. The humidity-sensitive electrical properties of the WO3 nanomaterial have been studied using d.c. measurements.

Cloacal gland foam enhances motility and disaggregation of spermatozoa in Japanese quail (Coturnix japonica).

The adult male Japanese quail produces white foam from the cloacal gland, which is transferred to the female proctodeum during natural mating. The physiological role of foam on quail spermatozoa is still unclear. Therefore, attempts have been made to understand the effect of cloacal foam on motility and metabolism of quail spermatozoa. The profile of various biochemical constitutes in the foam extract was investigated. The addition of foam extract to neat semen completely disaggregated the clumps of spermatozoa leading to vigorous motility. The metabolic rate (MBRT) of the spermatozoa was significantly increased with the addition of foam extract. The foam extract was sub fractionated into seven different fractions by using the molecular cut off devices. Among all the seven sub-fractions from the foam extract, the addition of < 1 KDa sub-fraction contained lactate and has enhanced sperm motility and metabolism. Another fraction (3-10 KDa) has non-protein and non-heparin components which completely disaggregated the clumped quail spermatozoa. However, the remaining fractions did not show any effect on quail spermatozoa. It can be concluded from the present investigation that the lactate present in foam might be a fuel for sperm metabolism and motility. Furthermore, low molecular weight (3-10 KDa) components in the foam may responsible for sperm disaggregation.

Characterization of lactate dehydrogenase enzyme in seminal plasma of Japanese quail (Coturnix coturnix japonica).

Lactate dehydrogenase enzyme present in quail seminal plasma has been characterized. Polyacrylamide gel electrophoresis and subsequently with LDH specific staining of seminal plasma revealed a single isozyme in quail semen. Studies on substrate inhibition, pH for optimum activity and inhibitor (urea) indicated the isozyme present in the quail semen has catalytic properties like LDH-1 viz. H-type. Furthermore, unlike other mammalian species, electrophoretic and kinetic investigations did not support the existence of semen specific LDH-X isozyme in quail semen. The effect of exogenous lactate and pyruvate on sperm metabolic activity was also studied. The addition of 1 mM lactate or pyruvate to quail semen increased sperm metabolic activity. Our results suggested that both pyruvate and lactate could be used by quail spermatozoa to maintain their basic functions. Since the H-type isozyme is important for conversion of lactate to pyruvate under anaerobic conditions it was postulated that exogenous lactate being converted into pyruvate via LDH present in semen may be used by sperm mitochondria to generate ATP. During conversion of lactate to pyruvate NADH is being generated that may be useful for maintaining sperm mitochondrial membrane potential.

Dynamics of a robust photo-induced insulator-metal transition driven by coherent and broad-band light in epitaxial films of La(0.625-y)Pr(y)Ca(0.375)MnO(3).

A dramatic drop of ≈5 orders of magnitude in the resistance (R) of La(0.175)Pr(0.45)Ca(0.375)MnO(3) epitaxial films upon exposure to optical photons derived from both continuous and pulsed lasers, as well as broad-band sources at temperatures (T) < 30 K is reported. The strength of change is a sensitive function of both the incident photon flux and temperature. Under isothermal conditions the photo-generated low resistance state persists eternally after removal of light. This non-equilibrium state is metallic, as revealed by the positive dR/dT for T ≤ T(p) (≈120 K). This electrically conducting state is presumably ferromagnetic as T(p) coincides with the temperature where a weak ferromagnetism sets in on cooling the insulating film from room temperature. To rule out the possibility of photon-induced local heating of the sample as a mechanism of the observed effects, photo-illumination experiments were performed under identical conditions on thin films of two non-charge-ordered manganites deposited on substrates of similar thermal conductivity. Our model for the observed transition encompasses a global charge-ordered state in which ferromagnetic metallic clusters of fraction p much less than the critical fraction p(c) for percolation exists at low temperatures. Photo-induced melting of the charge-ordered state increases this fraction beyond p(c) in a cumulative manner as successive pulses of light fall on the sample.

Pseudomesenteric cyst.

Mesenteric cyst and cystic mesenteric tumour are very rare abdominal growth, which is generally encountered, in the second decade of life. Pseudomesenteric cyst is another variant with traumatic and infective etiology is rare in itself. Only 14 cases have been reported previously in the Japanese literature. Emergency operation was performed in only 3 patients. The etiology of the pseudocyst manifested by acute abdomen was unknown [1]. A case of pseudomesenteric cyst presented in the emergency with acute abdomen is reported here.

Magnetotransport in epitaxial films of the degenerate semiconductor Zn(1-x)Co(x)O.

Magnetotransport measurements are performed over a broad range of temperature (T) and magnetic field (H) on highly degenerate n-type Zn(1-x)Co(x)O [Formula: see text] epitaxial films. The cobalt-free samples are characterized by a metallic resistivity ρ(T) down to 2 K, a negative and predominantly isotropic magnetoresistance (MR) and optical transmission above 85% in the visible range of the electromagnetic spectrum. X-ray diffraction measurements show that while for [Formula: see text], all cobalt atoms occupy the tetrahedral sites of the wurtzite structure of ZnO, a phase separation into CoO is seen for x>0.2. In the solution phase, we do not observe any signatures of a spontaneous ordering of the cobalt spins despite a large concentration of mobile electrons (>10(20) cm(-3)). The absence of anomalous Hall resistance is consistent with this observation. The carrier concentration (n) over the entire range of x remains above the Mott limit for the insulator-to-metal transition in a doped semiconductor. However, while the Co-free samples are metallic (T>2 K), we see a resistivity (ρ) minimum followed by lnT divergence of ρ(T) at low temperatures with increasing x. The magnetoresistance of these samples is negative and predominantly isotropic. Moreover, the MR tends to follow a logH behaviour at high fields. These observations, including the Kondo-like minimum in the resistivity, suggest s-d exchange dominated transport in these dilute magnetic semiconductors.

Conductometric determination of carbon in uranium carbide and its solution in nitric acid.

A simple but accurate method has been developed for the determination of carbon in uranium carbide powders/pellets as well as in solutions of uranyl nitrates. The methodology involves quantitative conversion of carbon present in the sample to carbon dioxide that is subsequently absorbed in a dilute solution of barium hydroxide. The conductivity shift of the barium hydroxide solution is monitored on-line continuously using a laboratory-built PC-based conductivity measurement system that has been developed in-house based on the direct conversion of conductance to the digital pulse frequency. A new gas absorption cell has been designed to ensure quantitative absorption during the residence time of the gas in the cell. The method is sensitive, accurate and precise to 1-3% at 600-1000 mug of carbon in samples of uranium carbide.