Lorenz-Mie scattering of focused light via complex focus fields: an analytic treatment

The Lorenz-Mie scattering of a wide class of focused electromagnetic fields off spherical particles is studied. The focused fields in question are constructed through complex focal displacements, leading to closed-form expressions that can exhibit several interesting physical properties, such as orbital and/or spin angular momentum, spatially-varying polarization, and a controllable degree of focusing. These fields constitute complete bases that can be considered as nonparaxial extensions of the standard Laguerre-Gauss beams and the recently proposed polynomials-of-Gaussians beams. Their analytic form turns out to lead also to closed-form expressions for their multipolar expansion. Such expansion can be used to compute the field scattered by a spherical particle and the resulting forces and torques exerted on it, for any relative position between the field's focus and the particle.Comment: 11 pages, 7 figure

Phylogenetic profiling of the Arabidopsis thaliana proteome: what proteins distinguish plants from other organisms?

BACKGROUND: The availability of the complete genome sequence of Arabidopsis thaliana together with those of other organisms provides an opportunity to decipher the genetic factors that define plant form and function. To begin this task, we have classified the nuclear protein-coding genes of Arabidopsis thaliana on the basis of their pattern of sequence similarity to organisms across the three domains of life. RESULTS: We identified 3,848 Arabidopsis proteins that are likely to be found solely within the plant lineage. More than half of these plant-specific proteins are of unknown function, emphasizing the general lack of knowledge of processes unique to plants. Plant-specific proteins that are membrane-associated and/or targeted to the mitochondria or chloroplasts are the most poorly characterized. Analyses of microarray data indicate that genes coding for plant-specific proteins, but not evolutionarily conserved proteins, are more likely to be expressed in an organ-specific manner. A large proportion (13%) of plant-specific proteins are transcription factors, whereas other basic cellular processes are under-represented, suggesting that evolution of plant-specific control of gene expression contributed to making plants different from other eukaryotes. CONCLUSIONS: We identified and characterized the Arabidopsis proteins that are most likely to be plant-specific. Our results provide a genome-wide assessment that supports the hypothesis that evolution of higher plant complexity and diversity is related to the evolution of regulatory mechanisms. Because proteins that are unique to the green plant lineage will not be studied in other model systems, they should be attractive priorities for future studies

Qualitative network models and genome-wide expression data define carbon/nitrogen-responsive molecular machines in Arabidopsis

BACKGROUND: Carbon (C) and nitrogen (N) metabolites can regulate gene expression in Arabidopsis thaliana. Here, we use multinetwork analysis of microarray data to identify molecular networks regulated by C and N in the Arabidopsis root system. RESULTS: We used the Arabidopsis whole genome Affymetrix gene chip to explore global gene expression responses in plants exposed transiently to a matrix of C and N treatments. We used ANOVA analysis to define quantitative models of regulation for all detected genes. Our results suggest that about half of the Arabidopsis transcriptome is regulated by C, N or CN interactions. We found ample evidence for interactions between C and N that include genes involved in metabolic pathways, protein degradation and auxin signaling. To provide a global, yet detailed, view of how the cell molecular network is adjusted in response to the CN treatments, we constructed a qualitative multinetwork model of the Arabidopsis metabolic and regulatory molecular network, including 6,176 genes, 1,459 metabolites and 230,900 interactions among them. We integrated the quantitative models of CN gene regulation with the wiring diagram in the multinetwork, and identified specific interacting genes in biological modules that respond to C, N or CN treatments. CONCLUSION: Our results indicate that CN regulation occurs at multiple levels, including potential post-transcriptional control by microRNAs. The network analysis of our systematic dataset of CN treatments indicates that CN sensing is a mechanism that coordinates the global and coordinated regulation of specific sets of molecular machines in the plant cell

Pseudoaneurisma de la arteria geniculada inferior medial tras reparación del ligamento del cruzado anterior.

Presentamos el caso de un varón de 24 años intervenido por una rotura crónica del ligamento cruzado anterior de rodilla izquierda. Se realizó una ligamentoplastia con técnica de cuatro fascículos con tendones ísquiotibiales. En el postoperatorio inmediato presentó un cuadro de hematoma en la zona de extracción de la plastia. Inicialmente se atribuyó a un sangrado muscular que se redujo con medidas médicas, el cuadro se repitió a los pocos días por lo que se decidió suspender el tratamiento con heparina de bajo peso molecular. Tras la mejoría se repite el hematoma, por lo que se realiza un angioTAC que muestra la presencia de un pseudoaneurisma de la arteria geniculada inferior medial. Ante la evolución tórpida del cuadro se decide la cirugía y se procede a ligar la arteria mencionada vaciándose el hematoma residual. El cuadro se resuelve sin incidencias, de modo que el paciente empieza su rehabilitación de modo habitual. Dada la infrecuencia de esta patología se revisa la bibliografía y su patogenia.We report the case of a 24 year old male with a chronic rupture of the anterior cruciate ligament in his left knee. We performed an anterior cruciate ligament reconstruction with four fascicles using the hamstrings tendon. In the immediate postoperative period, he presented a hematoma in the area of extraction plasty. Initially it was attributed to muscle bleeding and physical therapy (rest, ice and bandage) was prescribed. It reappeared few days later so it was decided to discontinue treatment with LMWH. Despite initial improvement, the haematoma reappeared so an angioCT Scan was performed showing medial inferior genicular artery pseudoaneurysm. The patient underwent a surgery for surgical wound exploration and ligation of the affected vessel. The patient improved and started the rehabilitation program as usual. Given the rarity of this disease and its pathogenesis literature is reviewed

The Role of Epigenetics in Cervical Cancer

Cervical cancer is the fourth most common type of cancer among women worldwide resulting in 528,475 new cases and 268,224 deaths. The principal etiological factor of cervical cancer is the persistent infection with high-risk types of human papillomaviruses (HPV), however is not sufficient, other factors like age, smoking, oral contraceptives, and genetic background are implicated in the development of this neoplasia. Although the understanding of cervical carcinogenesis has been increasing in recent decades, the epigenetic modifications (DNA methylation, histone modification, miRNAs and long non-coding RNAs) and its contribution to the development of cervical cancer remain largely unknown. In the next chapter, we will recapitulate the described findings on the alteration of epigenetic factors that, together with the persistent infection of HPV, could contribute to the malignant and invasive phenotype in cervical cancer