Hormonal signals involved in the regulation of cambial activity, xylogenesis and vessel patterning in trees

The radial growth of plant stem is based on the development of cribro-vascular cambium tissues. It affects the transport efficiency of water, mineral nutrients and photoassimilates and, ultimately, also plant height. The rate of cambial cell divisions for the assembly of new xylem and phloem tissue primordia and the rate of differentiation of the primordia into mature tissues determine the amount of biomass produced and, in the case of woody species, the wood quality. These complex physiological processes proceed at a rate which depends on several factors, acting at various levels: growth regulators, resource availability and environmental factors. Several hormonal signals and, more recently, further regulatory molecules, have been shown to be involved in the induction and maintenance of cambium and the formation of secondary vascular tissues. The control of xylem cell patterning is of particular interest, because it determines the diameter of xylem vessels, which is central to the efficiency of water and nutrient transport from roots to leaves through the stem and may strongly influence the growth in height of the tree. Increasing scientific evidence have proved the role of other hormones in cambial cell activities and the study of the hormonal signals and their crosstalking in cambial cells may foster our understanding of the dynamics of xylogenesis and of the mechanism of vessel size control along the stem. In this article, the role of the hormonal signals involved in the control of cambium and xylem development in trees and their crosstalking are reviewed

Techno-economic analysis for the integration of a power to fuel system with a CCS coal power plant

In this paper, an analysis of the integration of a carbon capture unit and a power to fuel system for methanol synthesis with a coal power plant is presented from the energetic, environmental and economic standpoints. The study is carried out in three different sections. In the first part, the impact of the integration of a carbon capture system (CCS ) and of a power to fuel plant (PtF) for methanol production is investigated in terms of plant average efficiency, fuel consumption,CO2 emissions. In the second part, the annual fixed and variable costs of the power plant, and the annual cost of electricity (COE) are assessed for different plant configurations. Additionally, future scenarios are analyzed considering the impact of European policies on the CO2 emission\u2019s cost, defined by the European Emission Trading System (ETS). Finally, an economic feasibility analysis of the power to fuel plant is performed and the methanol production is evaluated. Moreover, a sensitivity analysis is carried out to evaluate the impact of the most affecting parameters (electrical energy cost, the methanol selling price and the capital cost of the electrolyzer) in terms of Internal Rate of Return (IRR)

Hormonal responses to water deficit in cambial tissues of Populus alba L.

Changes of the concentration of bioactive gibberellins and abscisic acid in the cambial region of white poplar (Populus alba L.) were investigated in one-year-old plants, to highlight how these phytohormone signals are modulated in response to water deficit. Plants were cultivated in pots outdoor and, at the time of maximum cambial growth (T0), irrigation was withdrawn for 8 d, inducing a mild water deficit, thus mimicking a condition that is recurrent in mediterranean climates when white poplar attains its maximum growth rate. The water deficit was suspended by resuming irrigation (Tmax), throughout a recovery period of two weeks (Trec). Cambial tissues were sampled at T0, Tmax and Trec. Significant changes of leaf and stem relative water content, leaf water potential, stomatal conductance, transpiration, carbon assimilation, stem shrinkage and leaf number were induced by soil water shortage, which also negatively affected cambium development. Nevertheless, these responses were almost fully reversed following the resumption of irrigation. Water deficit induced the accumulation of large amounts of abscisic acid in cambial tissues, but the hormone was brought back to pre-stress levels after the recovery period. With regard to bioactive gibberellins, GA1 was several fold more abundant than GA4 and reached the greatest level in the plants recovering from the water status imbalance. The possible functions of gibberellins and abscisic acid in the response of cambial tissues to water deficit are discussed in view of the known physiological roles and molecular mechanisms of action of these hormonal signals

Calibration of the Mid-Infrared Tully-Fisher Relation

Distance measures on a coherent scale around the sky are required to address the outstanding cosmological problems of the Hubble Constant and of departures from the mean cosmic flow. The correlation between galaxy luminosities and rotation rates can be used to determine distances to many thousands of galaxies in a wide range of environments potentially out to 200 Mpc. Mid-infrared (3.6 microns) photometry with the Spitzer Space Telescope is particularly valuable as the source of the luminosities because it provides products of uniform quality across the sky. From a perch above the atmosphere, essentially the total magnitude of targets can be registered in exposures of a few minutes. Extinction is minimal and the flux is dominated by the light from old stars which is expected to correlate with the mass of the targets. In spite of the superior photometry, the correlation between mid-infrared luminosities and rotation rates extracted from neutral hydrogen profiles is slightly degraded from the correlation found with I band luminosities. A color correction recovers a correlation that provides comparable accuracy to that available at I band (~20% 1sigma in an individual distance) while retaining the advantages identified above. Without the color correction the relation between linewidth and [3.6] magnitudes is M^{b,i,k,a}_{[3.6]} = -20.34 - 9.74 (log W_{mx}^{i} -2.5). This description is found with a sample of 213 galaxies in 13 clusters that define the slope and 26 galaxies with Cepheid or tip of the red giant branch distances that define the zero point. A color corrected parameter M_{C_{[3.6]}} is constructed that has reduced scatter: M_{C_{[3.6]}} = -20.34 - 9.13 (log W_{mx}^{i} -2.5). Consideration of the 7 calibration clusters beyond 50 Mpc, outside the domain of obvious peculiar velocities, provides a preliminary Hubble Constant estimate of H_0=74+/-5 km/s/Mpc.Comment: Accepted for publication in The Astrophysical Journal, 14 pages, 11 figures, 4 table

Whipple's pancreaticoduodenectomy: Surgical technique and perioperative clinical outcomes in a single center

Introduction: Pancreatic cancer is the fourth cause of death from cancer in Western countries. The radical surgical resection is the only curative option for this pathology. The prevalence of this disease increases with age in population. The causes of pancreatic cancer are unknown, but we consider risk factors like smoke and tobacco usage, alcohol consumption coffee, history of diabetes or chronic pancreatitis. In this study we report our experience in the treatment of resectable pancreatic cancer and periampullary neoplasms with particular attention to evaluate the evolution of surgical technique and the clinical postoperative outcomes. Methods: In our Department between January 2010 and December 2014 we performed a total of 97 pancreaticoduodenectomy. We considered only resectable pancreatic cancer and periampullary neoplasms defined by absence of distant metastases, absence of local tumor extension to the celiac axis and hepatic artery as the lack of involvement of the superior mesenteric vasculature. None of these patients received neoadjuvant chemotherapy. Results: The mean age of these patients was 64.5 years. Jaundice was the commonest presenting symptom associated to anorexia and weight loss. The mean operative time was 295min (±55min). The mean blood loss was 450ml and median blood transfusion was 1 units. 12.1% of patients had an intra-abdominal complication. The commonest complication was Delayed Gastric Emptying responsable of increased length of hospital stay and readmission rate. Postoperative pancreatic fistula of grade C occurred in 4 patients. 2 patients developed a postpancreatectomy hemorrhage. Perioperative mortality was 4.1%. Conclusion: Pancreaticoduodenectomy is a complex surgical technique and the associated high morbidity and mortality resulted in initial reluctance to adopt this surgery for the management of pancreatic and periampullary tumors. Surgical outcomes of pancreatic surgery are better at high-volume experienced center reporting mortality rates below 5%. We perform an end-to-side duct-to-mucosa pancreaticojejunostomy with routinely use of internal pancreatic stent. However no one technique has been shown to definitely be the solution to the problem of postoperative pancreatic fistula. At our center we have a reasonable volume and our data are comparable to literature data

\u201cRelaparoscopic\u201d management of surgical complications: The experience of an Emergency Center

Background/aim: Laparotomy has been the approach of choice for re-operations in patients with surgical complications. The aim of this retrospective analysis was to evaluate the feasibility and the safety of laparoscopic approach for the management of general abdominal surgery complications. Materials and methods: We report a retrospective review of 75 patients who underwent laparoscopic evaluation for postoperative complications over a 4-year period. Primary outcomes (resolution rate by exclusive laparoscopic approach, conversion rate, further surgery rate) and secondary outcomes (mortality, hospitalization, prolonged ileus, wounds problems and median operative time) were evaluated. Results: Sixty-six patients (88 %) were managed with laparoscopic approach without conversion; of these, sixty-three patients (84 %) had no more or further complications and were discharged from hospital between 4 \ub1 3 days after \u201csecond-look\u201d surgery; three patients (4 %) developed postoperative complications requiring a third surgery. Nine cases (12 %) underwent conversion in open surgery after laparoscopic approach. Two elderly patients (2.7 %) died in intensive care unit, because of multi-organ failure syndrome. Median time elapsed between an intervention and another was about 2.5 \ub1 9.5 days. Mean operative time was 90 \ub1 150 min. Postoperative hospital stay was between 4.5 and 18 days. Discussion and conclusion: Laparoscopy has begun to be the preferred method to manage postoperative problems, but only few reports are available actually. Our experience in \u201crelaparoscopic\u201d management of surgical complications seems to suggest that laparoscopy \u201csecond look\u201d is an effective tool after open or laparoscopic surgery for the management of postoperative complications and it may avoid diagnostic delay and further laparotomy and related problems

Appendiceal mucinous neoplasms: An uncertain nosological entity. Report of a case

Introduction: Appendiceal mucocele is a relatively rare condition characterized by progressive dilation of the appendix caused by intraluminal accumulation of mucoid substance. Its incidence is 0.07 - 0,63% of all appendectomies performed. Case report: We report the case of a 70-year-old man who came to our observation with gravative pain in right lower abdominal region. A computed tomography abdominal scan revealed a cystic/tubular structure like an appendicular mass with wall enhancement but without calcifications suggestive of a mucocele. Into peritoneal cavity we found profuse mucinous material with a 1,5 cm size parietal nodule. We also identified a free perforation of the cecum with consensual spillage of gelatinous material mimicking a pseudomyxoma peritonei. We decided to perform a right hemicolectomy with excision of peritoneal lesion. Discussion: The controversy in the pathologic terminology can give rise to a clinical dilemma in terms of the management and follow-up plans. For mucosal hyperplasia and cystadenoma simple appendectomy is curative. Only in case of large base of implantation it may be necessary the resection of the ileum and caecum or right hemicolectomy. In case of mucinous cystoadenocarcinoma authors perform a right hemicolectomy. Conclusion: Appendiceal mucinous neoplasms are different pathological entities. The correct surgical management depends on size and location of lesion. A preoperative diagnosis is obviously needed in order to perform the correct treatment. CT abdominal scan is the better diagnostic tool, but different authors show their inability to reach a preoperative diagnosis in the larger majority of cases

Endometrial cancer: Robotic versus Laparoscopic treatment. Preliminary report

Laparoscopic approach is today the standard treatment for benign and malignant gynecological pathologies. To traditional laparoscopic surgery in the last 10 years we can add the possibility to use a robotic platform. The adoption of this system allows undoubted advantages as the three-dimensional vision, the absence of the physiological tremor with enhanced ergonomics and possibility of using articulable tools. In this study we analyzed the results of 18 patients with endometrial cancer (Stage I) treated with robotic approach. The results were compared with a selected sample of 26 patients, with the same characteristics, treated with traditional laparoscopic approach in the same period by the same surgical team. The mean total operative time was significantly longer for robotic than laparoscopic group (125.6 min vs 102.3 min). However, if to this operative time we remove the time of preparation (docking time) we obtain the following results: 102.5 min for robotic group and 95.7 min for the laparoscopic control group. Intra-operative blood loss are significantly lower in the robotic group than in laparoscopic group. The robotic treatment of gynecological cancer is a safe and feasible technique. The oncological results are also equivalent to those of traditional laparoscopic surgery with advantages in terms of precision and reduction of intraoperative bleeding. Additional clinical studies on larger samples and heterogeneous patients are necessary in order to clarify the real advantages of robotic treatment

Adrenal cavernous hemangioma: which correct decision making process?

Introduction: Cavernous hemangioma of the adrenal gland is a rare benign tumor characterized by the presence of blood-fil- led, dilated vascular spaces. These adrenal masses are usually non-functioning and the patients have no symptoms so the diagnosis is incidental. Methods: We performed a systematic literature review for all articles published until April 2015. The initial search identified 98 publications. We considered some characteristics: the mean age of the patients at diagnosis was 59 years (range 19 - 84); there were approximately 1.7 times more female patients than male patients; mean diameter of the lesions was 10.3 cm (range 2 - 25). Surgical treatment was more often open with midline or subcostal incision. Results: From literature analysis we know that small adrenal hemangiomas are usually asymptomatic. Only four patients in our literature review show endocrinologic disturbances with three cases of subclinical Cushing’s syndrome and a case of hyperaldo- steronism. The pre-operative radiologic features play a fundamental role for correct surgical approach. On enhanced Computed Tomography (CT) scan adrenal hemangiomas tend to be heterogeneous, hypodense lesions with high-density rim of tissue at the periphery. On Magnetic Resonance Imaging (MRI) common findings associated with adrenal hemangiomas are hypointense inhomo- geneous masses with central hyperintensity on T1 images and a high intensity peripheral rim on T2 images due to hemorrhage or necrosis. Conclusion: Laparoscopic adrenalectomy is considered the standard treatment in case of benign lesions. Some authors sugge- st that the main limitation during laparoscopic dissection for large and potentially malign adrenal tumors is incomplete resection and capsular disruption with increased risk of local recurrence and intra-abdominal neoplastic dissemination. We recommend for these patients an integrated multidisciplinary approach that considers endocrine studies, preoperative radiologic findings and the expe- rience of surgical team

Thomson scattering techniques in laser produced plasmas

Thomson scattering has been shown to be a valuable technique for measuring the plasma conditions in laser produced plasmas. Measurement techniques are discussed that use the ion-acoustic frequency measured from the collective Thomson-scattering spectrum to extract the electron temperature, ion temperature, plasma flow, and electron density in a laser produced plasma. In a recent study, they demonstrated a novel Thomson-scattering technique to measure the dispersion of ion-acoustic fluctuations that employing multiple color Thomson-scattering diagnostics. They obtained frequency-resolved Thomson-scattering spectra of the two separate thermal ion-acoustic fluctuations with significantly different wave vectors. This new technique allows a simultaneous time resolved local measurement of electron density and temperature. The plasma fluctuations are shown to become dispersive with increasing electron temperature. Furthermore, a Thomson-scattering technique to measure the electron temperature profile is presented where recent experiments have measured a large electron temperature gradient (Te = 1.4 keV to Te = 3.2 keV over 1.5-mm) along the axis of a 2-mm long hohlraum when heated asymmetrically