Area Duct Research Articles

Effects of lead exposure on salivary glands of rats: insights into the oxidative biochemistry and glandular morphology.

This study aimed to investigate the effects of lead (Pb) exposure on parotid and submandibular glands through morphological aspects as well as the systemic and salivary gland redox state. Male Wistar rats were exposed to 50mg/kg/day of Pb-acetate or distilled waterby intragastric gavage for 55days (n = 40). Blood samples were used for lipid peroxidation (LPO), glutathione (GSH), and trolox equivalent antioxidant capacity (TEAC) assays. Samples of salivary glands were analyzed by LPO, nitrites (NO), and antioxidant capacity against peroxyl radicals (ACAP) levels. Morphometric analyses (total stromal area [TSA], total parenchyma area [TPA], total ductal area [TDA], and total acinar area [TAA]) and immunohistochemistry for cytokeratin-19 (CK-19), metallothionein I/II (MT I/II), and anti-smooth muscle actin (α-SMA) were performed. The results revealed that exposure to Pb triggered systemic oxidative stress represented by lower GSH levels and increased TBARS/TEAC ratio in blood plasma. ACAP was reduced, while NO and LPO were increased in both parotid and submandibular. The morphological analyses showed increase on MT I/II expression, reduced CK-19 expression in both glands, and α-SMA reduced theimmunostaining only in the parotid glands. The morphometric analyses revealed an increase in TPA in both glands, while TAA was reduced only in submandibular glands and TDA was increased only in parotid glands. Our findings are pioneer in showing that long-term exposure to Pb is able to promote blood and glandular oxidative stress associated with cellular, morphological, and biochemical damage in both parotid and submandibular glands.

The Mutational and Transcriptional Landscapes of Hepatocarcinogenesis in a Rat Model.

SummaryHepatocellular carcinoma (HCC) initiation is characterized by stepwise accumulation of molecular alterations, during which the early events are largely unknown. Here, we presented a comprehensive genomic and transcriptomic landscape at stages of hepatitis, cirrhosis, and HCC by using a diethylnitrosamine-induced rat HCC model. We observed the early occurrence of gene instability and aberrant cancer associated signaling pathways in liver hepatitis. We further characterized the progressive molecular changes during hepatocarcinogenesis, wherein the intense rivalry between tumor-suppressive and oncogenic strengths occurred in cirrhosis stage. Despite the significant pathological difference, mutation signatures and expression landscape are highly similar between hepatitis and cirrhosis stages. Furthermore, we identified PI3K-Akt signaling pathway as a key pathway in the process of hepatocarcinogenesis through integrative analysis, and PIK3CD is a potential biomarker indicating HCC recurrence. The dynamic immune response during hepatocarcinogenesis, such as continuous decline of monocytes, suggests an immunological intervention strategy beyond chemoprevention for liver cancer.

Postablative 131I SPECT/CT Is Much More Sensitive Than Cervical Ultrasonography for the Detection of Thyroid Remnants in Patients After Total Thyroidectomy for Differentiated Thyroid Cancer

Evaluation of utility of cervical ultrasound (US) for detection of thyroid remnants (ThR) in patients after thyroidectomy for differentiated thyroid cancer. Included were 154 consecutive patients (17-89 years, 123 female and 31 male patients), without known cancer residues or cervical lymph nodes metastases, admitted for ThR ablation with I, 14 to 20 weeks after surgery. Neck uptake of I (Tup) and thyroglobulin were determined, and location and volume of ThR detected by cervical US were recorded. On days 3 to 4 after ablation (1.7-4.6GBq, 46-124.3 mCi I), neck SPECT/CT was performed, and I uptake foci were assigned to one of the regions as described below. The anterior neck was divided into 2 compartments: superior and inferior to lower margin of thyroid cartilage, and each compartment was subdivided into middle and lateral regions (in SPECT/CT, posterolateral and anterolateral regions were also marked out). I uptake sites and ThR detected by US, if congruent with SPECT/CT, were counted and analyzed. In total, 341 I uptake foci were found in 150 patients (97.4%) by SPECT/CT and 213 corresponding ThR in 118 patients (76.6%) by US. Ultrasound detected 30% to 46% of I uptake foci in superior lateral regions, 49% in pyramidal lobe/thyroglossal duct area (both P < 0.05), 74% to 77% in inferior lateral regions, and 22% in isthmus (both P > 0.05). Correlation between ThR volume and Tup was strong (r = 0.79), and that between ThR volume and thyroglobulin was weak (r = 0.24). Ultrasound is less sensitive than I posttherapy scans for ThR detection in patients after thyroidectomy, especially for remnants located above the lower margin of thyroid cartilage.

Determination of wall pressure flows at supersonic Mach numbers

This article investigates the wall pressure dissemination on a circular duct when the flow is exhausted into a CD nozzle. This study aims at to scrutinize the static pressure on the duct wall and its growth when the control is activated. The microjets are employed at the base at pitch circle radius (PCR) of 6.5 mm, and the radius of the microjets are 0.5 mm. The Mach numbers and the duct area ratio used are 2.56, Mach (M) 2 and 3. The lift to diameter ratio (L/D) and nozzle pressure ratio (NPR) of the study were from L/D = 10 to 1 and NPRs from 3 to 11. The NPRs tested were at different expansion level for M = 2. The oscillations in the duct flow field are seen when they are under expanded, and this trend continues for the total length of pipe. When the nozzles are ideally expanded the oscillations are absent as at this NPR only the Mach waves will be present. Similar trends are also seen at NPR 3 as well as whenever there is an adverse pressure gradient at Mach 2. With the decline in pipe length, the wavy nature of the flow is getting died out, and pressure recovery is smooth. The duct length and the backpressure has a crucial role to play in dictating the magnitude of wall pressure. L/D = 2 seems to be sufficient for M = 2 to continue to remain committed with the pipe, whereas for M = 3 the lowest duct size required is L/D = 4.

The effects of shape and size on duct-augmented horizontal axis turbine performance

This article seeks to contribute to knowledge on duct-augmented turbines by investigating the influence of the key geometric parameters of the duct on the turbine performance: (i) duct expansion angle and length, (ii) position of the duct relative to the rotor and (iii) added geometric features to the duct. A new analytic model is proposed for the duct-augmented turbine and used for the investigation. The proposed analytic model used in this study was developed with existing momentum and blade element analysis methodologies serving as its basis. Using the proposed analytic model, the duct length is found to be more influential on the duct turbine system performance than the duct expansion angle. In addition, the performance can be enhanced by addition of a flange to the duct trailing edge. The study also highlights that the optimum rotor location within a duct is slightly behind the minimum duct area.

Topographical-anatomical and clinical aspects of the assessment of Merzlikin-Paramonova's approach to liver surgeries

The purpose of the study was to assess results of Merzlikin-Paramonova's approach in liver surgeries. Material and Methods . The topographical-anatomical and spatial relationships were studied on 20 corpses, taking into account assessment criteria according to A.Yu. Sozon-Yaroshevich. In clinical settings, Merzlikin-Paramonova's approach was applied in the treatment of 81 patients with hepatic diseases (cancer, hemangioma, alveococcosis), who underwent radical and palliative surgeries. Short-and long-term treatment outcomes during a 5 year follow-up were analyzed. Merzlikin-Paramonova's approach provided a sufficient overview of the liver, easy manipulation in the area of large bile ducts and blood vessels, as well as the ability to perform lymphodissection and combined operations. Results. The Merzlikin-Paramonova's approach to liver surgeries has significant advantages over traditional surgical approaches, providing a good overview for revision of both primary and recurrent liver lesions. This surgical approach allowed the number of postoperative complications to be reduced due to less wound tension, rapid relief of pain and reduction in intra-abdominal hypertension, thus shortening the treatment time for patients. In the long-term postoperative period, the incidence of postoperative hernias decreased due to less damage to the nerve terminals of the anterior abdominal wall. Conclusion. Merzlikin-Paramonova's approach is slightly traumatic due to innervation and muscle structure of the abdominal wall, is more physiological for the patient, and has a low rate of complications. This approach provides a good access to the organ requiring surgery and is able to perform radical cytoreductive surgeries. Merzlikin-Paramonova's approach to liver surgeries can be recommended for active implementation in clinical practice.

Aluminum-Induced Toxicity in Salivary Glands of Mice After Long-term Exposure: Insights into the Redox State and Morphological Analyses.

Several studies indicate aluminum (Al) as a potent toxicant, mainly related to central nervous system disorders. However, investigations about the Al effects over salivary glands are still scarce. In this way, the present study aimed to investigate whether the Al chloride (AlCl3) is able of triggering oxidative stress in parotid and submandibular glands of mice and also, if any morphological impairment is observed. For this, twenty mice were divided into two groups: Exposed group (EG), which received 18.5mg/kg of AlCl3 by intragastric gavage for 60days and control group (CG), which received distilled water by intragastric gavage during the same period of time. After that, levels of reduced glutathione (GSH) and malonaldehyde (MDA) were analyzed and we performed morphological analyses by evaluating the area of parenchyma, stroma, acini, and ducts in both glands. Statistical analyses were performed by Student's t test and two-way ANOVA, adopting p < 0.05. No abnormal body weight was observed and data indicates that although both major salivary glands are susceptible to Al-induced oxidative stress, by increasing MDA and reducing GSH, only submandibular glands decreased the parenchyma and increased stroma area. Moreover, the submandibular glands showed smaller total area of acini and higher total area of ducts, in comparison with the control group. Notably, AlCl3 induces oxidative stress in both glands, however, submandibular glands showed to be more susceptible to Al effects than parotid glands. Our study gives evidences about Al toxicity in parotid and submandibular glands and claims for new investigations to understand more mechanisms of Al-induced toxicity.

Therapeutic tactics in cholelithiasis in children

There are still many questions concerning the choice of tactics for the treatment of cholelithiasis in childhood. For a long time, cholelithiasis traditionally considered a pathology of adults. Accordingly, virtually all research was devoted to the diagnosis and treatment of this pathology in the above group of patients.&#x0D; Purpose of research. Justification of tactics in surgical treatment of cholelithiasis in children.&#x0D; Patients and research methods. The work formed observations on 135 children aged from 2 to 17 years with cholelithiasis. In 70.4% of cases the disease is observed in girls and boys, respectively at 29.6%. 7.8% of patients have children disease arose against the backdrop of hemolytic anemia. One patient, who received urgent indications, had manifestations of mechanical jaundice: an increase in the level of common bilirubin and its direct fraction, pronounced jaundice of the skin. In the second group, 140 children with chronic stoneless cholecystitis were compared.&#x0D; Research result. All patients with cholelithiasis identified different ways deformation in the area of gallbladder duct. One of the major causes of cholelithiasis in children are changes in the gallbladder duct. No patient has ever been found in concretions extrahepatic biliary passages. In patients with chronic stone-free cholecystitis pathology in the area of bladder flow was not found.&#x0D; Conclusion. One of the major causes of gallstone disease in children are changes in the gallbladder duct, that most likely leads to obstruction of outflow of bile from the gall bladder, with the subsequent formation of concrements. Therefore, the conduct of conservative treatment of cholelithiasis in children appear to be ineffective and the method of choice in the treatment of this pathology can be a cholecystectomy.

Morphometry of the digestive glands of terrestrial mollusk Cornu aspersum (Gastropoda, Helicidae)

Histological and histochemical techniques were used to study specifics of parenchyma and stroma in digestive gland of Cornu aspersum. The parenchyma had 28.8 digestive ducts/mm2 on average (CV = 11.2&nbsp;%) round-to-oval, with average cross-section of 27700.9 µm2 (CV = 28.1 %). The duct area (79.8 % of parenchyma) and the area of inter-duct connective tissue (20.2 % of parenchyma) were in ratio 4 : 1. The gland completely lacked elastic fibers. The muscle elements between the ducts were of different shape and arrangement, on average 59.7 µm long (CV = 42.3&nbsp;%) and 1.41 µm wide (CV = 63.2&nbsp;%). The gland’s capsule was formed by three layers: epithelial, muscular, and the layer of collagen fibers. More than 60 % of the capsule’s thickness belonged to the muscular layer. The proportion of calcium cells in the digestive duct wall was 15.5 % (CV = 23.5&nbsp;%). Cells of digestive ducts contained a lot of vacuoles with brown granules (336.8 per 1 mm2, CV = 36.1&nbsp;%). The vacuole area was 2.2 % of all area of digestive gland (CV = 15.8&nbsp;%). The uneven location of muscle elements and brown granules in the glandular parenchyma indicated the functional features of the individual parts of the digestive gland.

Photoperiodic effect on the testicular transcriptome in broiler roosters

Information about the effects of photoperiod on the testicular transcriptome of broiler roosters is limited. The aim of the present study was to explore the effect of different photoperiodic regimes on gene expression in the testes of broiler breeder roosters. One hundred and twenty Arbor Acres broiler breeder roosters aged 20weeks were assigned to one of three groups (n=40) and subjected to different photoperiodic regimes: control (CTR; 12.5 L:11.5 D), short day (SD; 8 L:16 D) and long day (LD; 16 L:8 D). After 4weeks, the testes of 10 randomly selected birds from each group were dissected, sliced and haematoxylin-eosin stained. The testicular transcriptome of roosters from the SD and LD groups was determined by RNA sequencing (RNA-Seq), and the results were confirmed using quantitative real-time PCR. The seminiferous tubule area and sperm count increased significantly with the prolongation of photoperiod (p<.01). Additionally, the RNA-Seq results indicated that 387 genes were upregulated and 1,052 genes were downregulated in the LD group compared with those in the SD group. Several crucial genes involved in rooster testicular development and reproduction were also screened, including heat shock proteins 90, extracellular regulated protein kinases 1, phosphatidylinositol 3-kinase, adenosine 5'-monophosphate -activated protein kinase, BCL-6 and Smad3. The differentially expressed genes were enriched in the mammalian targets of rapamycin (mTOR), forkhead box (FoxO), transforming growth factor beta (TGF-β) and insulin signalling pathway. In conclusion, a 16hr photoperiod for 4weeks increased the seminiferous tubule duct area and promoted spermatogenesis in the rooster's testicles, and the mTOR, FoxO, TGF-β and insulin signalling pathways may be involved.

Dwarf Mistletoe Infection Interacts with Tree Growth Rate to Produce Opposing Direct and Indirect Effects on Resin Duct Defenses in Lodgepole Pine

Research Highlights: I sought to disentangle the influences of tree age, growth rate, and dwarf mistletoe infection on resin duct defenses in lodgepole pine, Pinus contorta Douglas ex Loudon, revealing the presence of direct positive and indirect negative effects of mistletoe on defenses. Background and Objectives: For protection against natural enemies, pines produce and store oleoresin (resin) in ‘resin ducts’ that occur throughout the tree. Dwarf mistletoe, Arceuthobium americanum Nutt. ex Engelm. (hereafter “mistletoe”), is a widespread parasitic plant affecting the pines of western North America. Infection by mistletoe can suppress pine growth and increase the probability of insect attack—possibly due to a reduction in resin duct defenses or in the potency of chemical defenses at higher levels of mistletoe infection, as reported in Pinus banksiana Lamb. However, the influence of mistletoe infection on defenses in other pine species remains unclear. I hypothesized that mistletoe infection would induce greater resin duct defenses in P. contorta while simultaneously suppressing annual growth, which was expected to reduce defenses. Materials and Methods: Using increment cores from P. contorta trees occurring in a subalpine forest of Colorado, USA, I quantified tree age, annual growth, annual resin duct production (#/annual ring), and cross-sectional area (mm2 of resin ducts/annual ring). Results: Mistletoe infection increased with tree age and had a direct positive relationship with resin duct defenses. However, mistletoe infection also had an indirect negative influence on defenses via the suppression of annual growth. Conclusions: Through the combined direct and indirect effects, mistletoe infection had a net positive impact on resin duct production but a net negative impact on the total resin duct area. This finding highlights the complexity of pine defense responses to natural enemies and that future work is needed to understand how these responses influence overall levels of resistance and the risk of mortality.

Exploration on the Structure Parameters of Nozzle-to-Throat Clearance in Vacuum Generator

Nozzle-to-throat clearance is one of the main factors affecting the injection coefficient of the vacuum generator. The increase of nozzle-to-throat clearance will lead to the aggrandizement of the annular duct area which the driving fluid passes, thereby amplifying the ejector flow rate of ejector tube and the injection coefficient. On the contrary, Keenan [1] obtained the result through the experiment that the injection coefficient decreased as nozzle-to-throat clearance increases, because the accretion in nozzle-to-throat clearance would increase the pressure of inlet plane of the mixing chamber, resulting in the decrease of the driving pressure difference of the driving fluid, hence the injection coefficient diminished. In this paper, the numerical simulation method is used to obtain the optimal nozzle-to-throat clearance parameter size.

A Novel Biodegradable Tubular Stent Prevents Pancreaticojejunal Anastomotic Stricture

Stricture of pancreatic-enteric anastomoses is a major late complication of a pancreaticoduodenectomy for the treatment of a periampullary tumor and can lead to exocrine and endocrine insufficiency such as malnutrition and diabetes mellitus. We investigated the safety and efficacy of a biodegradable tubular stent (BTS) for preventing a pancreaticojejunostomy (PJ) anastomotic stricture in both a rat and porcine model. The BTS was manufactured using a terpolymer comprising poly p-dioxanone, trimethylene carbonate, and glycolide. A cohort of 42 rats was randomized into 7 groups of 6 animals each after BTS placement into the duodenum for the biodegradation assay. A total of 12 pigs were randomized equally into a control and BTS placement group. The effectiveness of the BTS was assessed by comparing radiologic images with histologic results. Surgical procedures and/or BTS placements were technically successful in all animals. The median mass losses of the removed BTS samples from the rat duodenum were 2.1, 6.8, 11.2, 19.4, 26.1, and 56.8% at 1, 2, 3, 4, 6, and 8 weeks, respectively. The BTS had completely degraded at 12 weeks in the rats. In the porcine PJ model, the mean luminal diameter and area of the pancreatic duct in the control group was significantly larger than in the BTS group (all p < 0.05). BTS placement thus appears to be safe and effective procedure for the prevention of PJ anastomotic stricture. These devices have the potential to be used as a temporary stent placement to treat pancreatic-enteric anastomoses, but further investigations are required for optimization in human.

Considering blood samples for early diagnosis of prostate cancer by evaluating prostate cancer antigen 3 expression values

Background: Prostate cancer antigen 3 (PCA3) is the most specific biomarker for an early diagnosis of prostate cancer (PCa), and it is routinely evaluated in urine samples. Recent investigations consider blood as a reliable source to determine PCA3 expression levels and fast diagnosis of PCa since in addition to bacterial and viral contaminations and the hygienic problems, if the area of the prostatic duct is not involved PCa, the obtained urine samples may not contain any cancerous cells. Materials and Methods: This study investigated blood expression values of the PCA3 gene in patients with PCa and multiple endocrine neoplasia compared with normal volunteers in an Iranian population. A total of 150 blood samples from three groups were assessed for PCA3 expression using real-time polymerase chain reaction. Prostate-specific antigen (PSA) serum levels, age, and family history of PCa were also analyzed. Results: PCA3 expression analysis showed a significant increase in PCa patients and in patients with PSA serum levels higher than 7 ng/ml (P = 0.005 and P= 0.0011, respectively). Analysis of blood samples from men with an older age and positive family history also showed significant PCA3 expression values. Results of this study suggests that evaluating PCA3 gene expression in blood samples is an adequate method for an early diagnosis of PCa. The decision to perform a prostate biopsy should be made more cautiously in patients with a PSA serum level between 4 and 7 ng/ml. Patients with a positive PCa family history and higher age should be considered for PCa diagnostic procedures.Conclusion: Blood samples can be considered for PCA3 evaluating as a promising alternative of urine samples for PCa diagnosis.

The key role of pancreatic fibrosis severity in the surgical treatment algorithm of patients with chronic pancreatitis

The aim of the work was to improve the results of surgical treatment of complicated forms of chronic pancreatitis. Materials and methods: The results of surgical treatment of 181 patients with complicated forms of chronic pancreatitis have been analyzed. All these patients were treated in surgical clinic of 2 nd medical faculty of National Pyrogov Memorial Medical University in Vinnytsya. Results: It is possible preoperative indirectly assess the severity of fibro- degenerative changes in pancreas, that includes 1 - the definition of pain type; 2 - CT or MRI (Marseilles-Rome classification); 3 - assessment of the stage of chronic pancreatitis (Büchler classification); 4 - patient's nutrition status and preoperative differential diagnosis with pancreatic cancer; 5 - assessment of the fibrosis severity (elastomers). The key point in treatment depended on intraoperative examination: detection of strictures of the main pancreatic duct (pacemaker of chronic pancreatitis); the tissue pressure resistance to the liquid, which is the maximum value> 200 mmHg, in the region of stricture and falls in other parts of the pancreas; pressure in the main pancreas duct, which rises only in 59.5% of patients. The head of the pancreas was involved in the pathological process in 83.8%, in 16.2% it was isolated in the isthmus or the body and tail of the pancreas. In general, the distal pancreas was involved in 37.8%. At computer morphometry of histological samples, the area of connective tissue fields reached 81.4 ± 6.62%, preserved exocrine part in 4.87 ± 1.62%, endocrine - 1.92 ± 0.12%, total area of ducts - 6 , 47 ± 1.12%. Conclusions: The combined Frey-Izbickiy local resection provides a wide excision of the pacemaker (stricture) of chronic pancreatitis. In case of extrapancreatic complications or repeated surgical interventions on the pancreas due to chronic pancreatitis, this effect can be achieved by pancreatoduodenal resection.

Effects of oestrous synchronization with altrenogest in gilts on endometrial and embryonic characteristics

The use of altrenogest (ALT) supplementation for oestrous synchronization improves subsequent reproductive performance of gilts and sows. However, the causes of this improvement in reproductive performance after ALT treatment are not fully/clearly understood. The objective of this study was to evaluate the effects of ALT supplementation for oestrous synchronization in gilts on the endometrial glands and embryonic development characteristics at 28 days of pregnancy. Pregnant gilts were divided into two experimental treatments: Control (did not receive ALT; n = 9 gilts) and ALT (ALT feeding at 20 mg/day for 18 days; n = 9 gilts). At 28 days of pregnancy, six gilts from each treatment were slaughtered, and reproductive tracts were immediately evaluated. There was no statistical difference (P > 0.05) between treatments regarding ovulation rate, number of embryos, number of vital embryos and number of non-vital embryos. Embryo weight, length and embryonic vesicle weight were lower in ALT treatment compared with Control (P < 0.01), and it was lower in the cervical uterine region compared with apex uterine region, respectively (P < 0.05). Higher values of gland duct area, gland duct perimeter, percentage of the glandular area and total endometrial area were observed in ALT treatment compared with Control (P < 0.05). The use of ALT during 18 days for oestrous synchronization in gilts increased the gland duct area, perimeter and total endometrial area but did not increase the embryo number and embryo size at day 28 of pregnancy.

Anatomy, chlorophyll content and photosynthetic performance in current-year and previous-year Aleppo pine (Pinus halepensis Mill.) needles

Aleppo pine (Pinus halepensis) is a widespread Mediterranean woody species. Needles usually fall off the tree after the second year, which can be the reason for substantial crown defoliation under extreme environmental stress. The aim of the present investigation was to compare the anatomy, chlorophyll content and photosynthetic performance in current-year (CY) and previous-year (PY) Aleppo pine needles. Chlorophyll concentrations were determined spectrophotometrically, while photosynthetic performance was determined by measuring the increase in chlorophyll a fluorescence (the JIP test). The obtained results revealed that concentrations of chlorophylls a and b were almost twice as great in PY needles as in CY ones. The chlorophyll a to b ratio and values of the maximum quantum yield of photosystem II (Fv/Fm) showed no statistically significant difference between CY and PY needles. However, the performance index (PIABS) was significantly higher in CY needles compared to PY ones. Analysis of PIABS components revealed that CY needles had increased electron transport beyond the primary electron acceptor, QA -, which was associated with a lower value of variable fluorescence at 2 ms (VJ) in comparison with PY needles. Also, some differences were observed in needle anatomy. Current-year needles had an increased proportion of mesophyll tissue, together with decreased proportions of vascular cylinder and resin duct areas. Also, many more starch grains were present in PY than in CY needles. Based on the presented results, it can be concluded that despite considerably lower chlorophyll content, CY needles exhibited photosynthetic performance better than that of older needles, which is an unusual phenomenon in woody species.

Neutral and Climate-Driven Adaptive Processes Contribute to Explain Population Variation in Resin Duct Traits in a Mediterranean Pine Species.

Resin ducts are important anatomical defensive traits related to biotic resistance in conifers. Previous studies have reported intraspecific genetic variation in resin duct characteristics. However, little is currently known about the micro-evolutionary patterns and adaptive value of these defensive structures. Here, we quantified inter-population genetic variation in resin duct features and their inducibility in Pinus pinaster and assessed whether such variation was associated with climate gradients. To that end, we characterized the resin duct system of 2-year-old saplings from 10 populations across the species’ distribution range. We measured axial resin duct features (density, mean size, and percentage conductive area of resin ducts) and their inducibility in response to methyl jasmonate. Genotyping of single nucleotide polymorphisms allowed to account for the population genetic structure in our models in order to avoid spurious correlations between resin duct characteristics and climate. We found large inter-population variation in resin duct density and conductive area, but not in their inducibility. Our results suggest that population variation in the percentage conductive area of resin ducts likely arise from adaptation to local climate conditions. This study highlights the adaptive relevance of resin ducts and helps to shed light on the micro-evolutionary patterns of resin-based defenses in conifers.

Effect of air inlet duct features and grater thickness on cooking banana drying characteristics using active indirect mode solar dryer

The effect of air inlet duct area of an active indirect mode solar dryer on drying of cooking banana was studied. The factors considered for the experiment were: air inlet duct area and grater size of the product. The factors were considered at five different levels using the Central Rotatable Composite Design. The air inlet shapes considered were: square, rectangular, circular and triangular, while the product sizes were 4, 8, 12, 16 and 20 mm respectively. The experimental design gave a total of 52 runs for each experiment. The experiment was replicated three times with sun drying of the product as control. Data were obtained on a two hourly interval between 8:00 am to 6:00 pm on each drying day. Drying was achieved between 9 to 26 hours of drying, as compared to the control, which was between 15 to 37 hours depending on the grater size. The dryers were able to conserve between 26.67 to 37.84 % of the drying time for the products. The air inlet duct area had significant effect on the drying rate of the product at 5% level of significance. Keywords: Air inlet, drying rate, moisture content, sun drying, cooking banana

Whitebark pine (Pinus albicaulis) growth and defense in response to mountain pine beetle outbreaks

Whitebark pine (Pinus albicaulis) is a critical forest species of Northern Rocky Mountain upper subalpine ecosystems, yet little is known about the physiological response of whitebark pine to disturbance (e.g. fire, bark beetles, and pathogens) across a range of diverse environmental gradients. Resin-based defenses have long been recognized as the primary mechanism by which conifers respond to attack by bark beetles and pathogens and several studies have linked resin duct properties to survivorship during periods of increased beetle activity. However, to our knowledge, no studies have compared axial resin ducts in the secondary xylem of whitebark pine across pairs of living and dead whitebark pine trees to better understand survivorship following multiple disturbances including mountain pine beetle and white pine blister rust. We found a clear distinction in growth and defense characteristics between live and dead whitebark pine. Across our study sites on the Flathead Indian Reservation in northwestern Montana, live whitebark pine produced larger resin ducts with a greater annual investment in resin-based defenses than whitebark pine that died. Resin duct size, duct area, and relative duct area were all greater in live whitebark pine (by 56%, 48%, and 57%, respectively) and these were the most important variables influencing whitebark pine survivorship. In contrast, whitebark pine that had died grew faster over time (22% larger ring widths) than their live counterparts and also produced more resin duct structures (20% more ducts on average). Whitebark pine at our study sites exhibit differing strategies in the allocation of resources toward growth and defense, with the majority of survivors of recent disturbance investing more in defensive structures than growth. Our results support the idea that maintaining genetic variability and the associated suite of differing physiological traits promotes diverse response strategies to a complex array of biophysical and biological stressors that might leave a species vulnerable to extinction across its range.