Frequency and time profiles of metric wave isolated Type I solar noise storm bursts at high spectral and temporal resolution

Type I noise storms constitute a sizeable faction of the active-Sun radio emission component. Observations of isolated instances of such bursts, in the swept-frequency-mode at metric wavelengths, have remained sparse, with several unfilled regions in the frequency coverage. Dynamic spectra of the burst radiation, in the 30 - 130 MHz band, obtained from the recently commissioned digital High Resolution Spectrograph (HRS) at the Gauribidanur Radio Observatory, on account of the superior frequency and time resolution, have unravelled in explicit detail the temporal and spectral profiles of isolated bursts. Apart from presenting details on their fundamental emission features, the time and frequency profile symmetry, with reference to custom-specific Gaussian distributions, has been chosen as the nodal criterion to statistically explain the state of the source regions in the vicinity of magnetic reconnections, the latent excitation agent that contributes to plasma wave energetics, and the quenching phenomenon that causes damping of the burst emission.Comment: 9 pages 7 black and white / grey-scale figures (inclusive of 3 composite). MNRAS - accepte

Localization and Fluctuations in Quantum Kicked Rotors

We address the issue of fluctuations, about an exponential lineshape, in a pair of one-dimensional kicked quantum systems exhibiting dynamical localization. An exact renormalization scheme establishes the fractal character of the fluctuations and provides a new method to compute the localization length in terms of the fluctuations. In the case of a linear rotor, the fluctuations are independent of the kicking parameter $k$ and exhibit self-similarity for certain values of the quasienergy. For given $k$, the asymptotic localization length is a good characteristic of the localized lineshapes for all quasienergies. This is in stark contrast to the quadratic rotor, where the fluctuations depend upon the strength of the kicking and exhibit local "resonances". These resonances result in strong deviations of the localization length from the asymptotic value. The consequences are particularly pronounced when considering the time evolution of a packet made up of several quasienergy states.Comment: REVTEV Document. 9 pages, 4 figures submitted to PR

Robotic Partial Nephrectomy for a Peripheral Renal Tumor

Partial nephrectomy (PN) is the preferred surgical treatment for T1 renal tumors whenever technically feasible. When properly performed, it allows preservation of nephron mass without compromising oncologic outcomes. This reduces the postoperative risk of renal insufficiency, which translates into better overall survival for the patients. PN can be technically challenging, because it requires the surgeon to complete the tasks of tumor excision, hemostasis and renorrhaphy, all within an ischemic time of preferably below 30 minutes. The surgeon needs to avoid violating the tumor margins while leaving behind the maximal parenchymal volume at the same time. Variations such as zero ischemia, early unclamping, and selective clamping have been developed in an attempt to reduce the negative impact of renal ischemia, but inevitably add to the steep learning curves for any surgeon. Being able to appreciate the fine details of each surgical step in PN is the fundamental basis to the success of this surgery. The use of the robotic assistance allows a good combination of the minimally invasive nature of laparoscopic surgery and the surgical exposure and dexterity of open surgery. It also allows the use of adjuncts such as concurrent ultrasound assessment of the renal mass and intraoperative fluorescence to aid the identification of tumor margins, all with a simple hand switch at the console. Robot-assisted laparoscopic PN is now the most commonly performed type of PN in the United States and is gaining acceptance on the global scale. In this video, we illustrate the steps of robot-assisted laparoscopic PN and highlight the technical key points for success

The Purposes and Accountability of the Corporation in Contemporary Society: Corporate Governance at a Crossroads

Little attention has been paid to how the governance structures of public corporations adapt to structural changes in the social, political, economic and legal environments in which they operate. Bradley et al chronicle the recent changes in the conduct of business enterprise and establish the necessary conditions for a system of corporate governance capable of accommodating these changes

A Clinicopathological study and Treatment of Masses in Sinonasal Cavity

INTRODUCTION: Sinonasal malignancies, a highly heterogeneous group of cancers, account for less than one percentage of the cancers and less than three percentage of all digeastive system tumors. These lesions may originate from any of the histopathologic components of the sinonasal cavities, including Schneiderian mucosa, minor salivary glands, neural tissue, and lymphatics. 60% of these tumors arise in the maxilla, but twenty percentage come from cavity of nose, five percentage come from sinus of ethimoid, three percentage from the sinus of frontal, sinus of sphenoid. Squamous cell carcinomas are more common within the nasal cavity or maxillary sinus, whereas tumors of the ethmoid sinus and superior nasal vault are usually adenocarcinomas. Mucosal melanoma frequently originates within the nasal cavity, particularly along the lateral nasal side wall and inferior turbinates. Although traditional risk factors for sinonasal cancers have included exposure to nickel, wood dust, and tobacco, no predisposing factors are identified in most patients. Recent reports suggest that HPV promotes the development of some sinonasal squamous cancers. Thus the key to the diagnosis and management of sinonasal malignancies lies in the eliciting of proper history, clinical features and investigation protocol to detect the tumour at the early stage and provide the appropriate treatment for the patient,thereby increasing the survival rate. This study was conducted to assess the importance of detecting the clinical features, detecting the lesion through histopathology and imaging to arrive at the diagnosis at an earlier stage and evaluating the treatment protocol. AIMS OF STUDY In sinonasal tumours, 1. To correlate the symptoms, signs with the clinical staging. 2. To correlate the clinical features with the pathological staging. 3. To study the incidence of age and sex of the tumour. 4. To study the incidence of TNM staging and broder’s staging among the patients. 5. To correlate the histological diagnosis and treatment plan. MATERIALS AND METHODS: The study was done in Government Rajaji Hospital,Madurai medical college, Madurai, from October 2010 to October 2012. Out of the patients who attended the outpatient department during the period, those with symptoms and signs suggestive of sinonasal masses were screened further. After thorough clinical examination, the patients were subjected to Endoscopy into the nasal cavity and computed tomography scan for the sinonasal area were performed. Those with histologically confirmed benign and malignant tumors were selected for the study. The total number of 50 patients were selected for the study and their surgical and non surgical outcomes were noted. CONCLUSION: The work up, management and follow up of sinonasal tumours is complicated by the multiple potential sites and stages of development. Various array of options of management of tumours are radical surgery alone, surgery followed by radiotherapy, chemoradiotherapy and stereotactic gamma knife surgery. This study was performed because of the high incidence of the sinonasal tumours in Government Rajaji Hospital, Madurai. Combined modality approach was entitled for the patients under study which included otolaryngologist, radiotherapist, neurosurgeon, medical oncologist, surgical oncologist, psychiatrist, psychologist, radiologist, pathologist, dentist, nutritionist, social worker. This approach had an advantage of earlier diagnosis of the tumours, accurate delineation of the tumour, precise and appropriate treatment. All these factors improved the prognosis and thus extended the survival rate of the patients. The role of surgery followed by radiotherapy played a pivotal role in the stage I and stage II tumours where a complete cure was almost possible. The role of radiotherapy in stage III and stage IV played a good palliative role in inoperable cases. Complete tumour removal was very much possible both through open and endoscopic methods. The role of chemotherapy combine with radiotherapy was efficient in preventing recurrence and residual tumour rates. Induction chemotherapy followed by maintenance therapy reduced the side effects of chemotherapeutic agents, The goals of treatment can be attained by multidisplinary and multi modality approach