Energy, Laplacian energy of double graphs and new families of equienergetic graphs

For a graph $G$ with vertex set $V(G)=\{v_1, v_2, \cdots, v_n\}$, the extended double cover $G^*$ is a bipartite graph with bipartition (X, Y), $X=\{x_1, x_2, \cdots, x_n\}$ and $Y=\{y_1, y_2, \cdots, y_n\}$, where two vertices $x_i$ and $y_j$ are adjacent if and only if $i=j$ or $v_i$ adjacent to $v_j$ in $G$. The double graph $D[G]$ of $G$ is a graph obtained by taking two copies of $G$ and joining each vertex in one copy with the neighbours of corresponding vertex in another copy. In this paper we study energy and Laplacian energy of the graphs $G^*$ and $D[G]$, $L$-spectra of $G^{k*}$ the $k$-th iterated extended double cover of $G$. We obtain a formula for the number of spanning trees of $G^*$. We also obtain some new families of equienergetic and $L$-equienergetic graphs.Comment: 23 pages, 1 figur

War without weapons:constitution of healthy and pathological phenotypes associated with polymorphisms in genes involved in the maintenance of genome integrity

Capacity to repair DNA damage may vary significantly between individuals coming out as healthy on routine physical and laboratory examinations. This variance does not generally cause distress or disease unless in case that specific triggers are present, but, taken together with other factors, may increase the risk for certain types of cancer or may modulate the outcome of anticancer therapies. Carriership of certain polymorphic variants in DNA repair genes may also modify the course of the normal process of aging. The present paper reviews the role of some of the common polymorphisms in DNA repair genes and in genes involved in the maintenance of genomic integrity; and their association, separately or in combination, with the ‘healthy’ phenotype and with certain diseases and conditions related to exposure to increased levels of oxidative damage

Repair, abort, ignore? Strategies for dealing with UV damage

DNA repair is a prominent member of the nuclear transactions triad (replication, transcription, and repair). Sophisticated mechanisms govern the cellular process of decision-making (to repair or not to repair, to proceed with cell cycle or not and, eventually, to let the cell survive or die) and the temporal and spatial distribution of the DNA repair activities. UV radiation is a very common and virtually unavoidable mutagen whose carcinogenic potential seems to accumulate over time. Various strategies have been developed to avoid or decrease UV damage to cellular DNA, based on prevention of exposure as well as on post-irradiation measures. It is, however, important to acknowledge that the individual capacity for DNA repair varies during the life of the individual and must, therefore, be assessed so as to determine whether the individual is coping with environmental UV damage. Assessment of individual repair capacity might greatly modify the existing therapeutic strategies for common cancers and ought to become a routine part of health prophylaxis

Differential genetic advantages in youth and in aging, or how to die healthy

Human society ages at a steady rate, that is, the proportion of adult and elderly individuals increases constantly because of improved living conditions and the advances in medical care. This means that very soon the tradeoff between the advantages in old age conferred by alleles disadvantageous or neutral in young age would begin to show, providing the fascinating opportunity of studying the interplay between genetic factors and environment outside the framework of reproductive capacity and in the unique milieu of the aging cell. Being healthy and/or health-conscious in youth does not guarantee for successful aging or even that the person would live up to the average life expectancy of the population. Therefore, successful aging and longevity are related to a healthy-conscious attitude to a degree only. The present paper reviews the basic genetic and evolutionary mechanisms which have operated during human history so as to ensure survival of humankind and the possible factors preventing or contributing to successful aging

ATM in focus:a damage sensor and cancer target

The ability of a cell to conserve and maintain its native DNA sequence is fundamental for the survival and normal functioning of the whole organism and protection from cancer development. Here we review recently obtained results and current topics concerning the role of the ataxia-telangiectasia mutated (ATM) protein kinase as a damage sensor and its potential as therapeutic target for treating cancer. This monograph discusses DNA repair mechanisms activated after DNA double-strand breaks (DSBs), i.e. non-homologous end joining, homologous recombination and single strand annealing and the role of ATM in the above types of repair. In addition to DNA repair, ATM participates in a diverse set of physiological processes involving metabolic regulation, oxidative stress, transcriptional modulation, protein degradation and cell proliferation. Full understanding of the complexity of ATM functions and the design of therapeutics that modulate its activity to combat diseases such as cancer necessitates parallel theoretical and experimental efforts. This could be best addressed by employing a systems biology approach, involving mathematical modelling of cell signalling pathways

Konsep Harga dalam Ekonomi Islam (Telah Pemikiran Ibn Taimiyah)

Term ekonomi menjadi sesuatu yang urgen untuk didiskusikan bahkan dirancang sedemikian rupa untuk menopang pilar kemajuan suatu peradaban umat manusia. Islam sebagai agama samawi terakhir memiliki sumber yang potensial dalam mengembangkan khazanah ekonomi baik mikro maupun makro, maupun skala domestik, regional bahkan Internasional. Adalah Rasulullah SAW yang suatu ketika ditanya oleh komunitas masyarakatnya tentang fluktuasi harga yang cenderung memberatkan masyarakat pada saat itu dengan memberikan jawaban seolah-oleh lepas dari tanggungjawab, telah menimbulkan multi tafsir di kalangan cendekia Islam sejak awal perkembangannya hingga kini. Di kalangan sahabat yang di ataranya adalah Umar ibn al-Khattab merespon prilaku Rasulullah adalah kasuistis dan tidak universal sehingga intervensi pemerintah dalam hal ini adalah dibolehkan bila didasarkan pada kemaslahatan umat. Sedangkan di kalangan ulama madzhab sunni secar garis besar terbagi menjadi dua pendapat: Kelompok pertama, memahami matan hadis Rasul itu dengan tekstual sehingga dalam kondisi apapun dan bagaimanapun, pemerintah tidak dibenarkan intervensi mengenai harga. Kelompok kedua, membolehkan adanya intervensi pemerintah terhadap harga komoditas perdagangan, bila terjadi indikasi adanya distorsi pasar. Hal ini dilakukan untuk menjadikan pasar sebagai instrument ekonomi yang akuntabel

وجوه الفلسفي للحكم الإسلامي في ضوء القرآن والسنة

الفلسفة هي الدراسة للحصول على معرفة الحقيقة من العلوم الرياضية وغير الرياضية والعلوم الدينية. في القرن الثالث والرابع من الهجرية، وأصبحت الفلسفة دراسة مكثفة بين فلاسفة الإسلام حتى انتاجت المحصولات العلمية الضخمة في العديد من التخصصات. فلسفة الشريعة الإسلامية هي دراسة الشريعة الإسلامية منهجية عن المبادئ والأسس، والقواعد، وأسرار الشريعة الإسلامية باقتران علم الوجودي، المعرفي والقيمي. الجرجاوي في كتابه " تاج العارفين " يبحث عن حكمة وفلسفة الشريعة الإسلامية، وهو يقدم ثلاثة مناهج: فلسفة التشريع ، فلسفة وحكمة الشريعة أو فلسفة التشريع. فلسفة التشريع تبحث عن: أسسس، ومبادئ، ومصادر، وقواعد وأهداف الشريعة الإسلامية. فلسفة الشريعة تبحث عن: أسرار، والميزات وطبائع الشريعة الإسلامية. وأما حكمة الشريعة أو فلسفة التشريع تبحث عن: أسرار وأهداف كل حكم شرعيّ للبشر. القرآن والسنة هي المصادر الرئيسية لدراسة فلسفة الشريعة الإسلامية مع كل معيار. على سبيل المثال في قانون الأسرة حول الحكمة من الزواج، مثل تلبية الاحتياجات الأساسية للبشرية في استمرار النسل و تكثير عدد البشر على وجه الأرض