Normal, dust-obscured galaxies in the epoch of reionization.

Over the past decades, rest-frame ultraviolet (UV) observations have provided large samples of UV luminous galaxies at redshift (z) greater than 6 (refs. 1-3), during the so-called epoch of reionization. While a few of these UV-identified galaxies revealed substantial dust reservoirs4-7, very heavily dust-obscured sources at these early times have remained elusive. They are limited to a rare population of extreme starburst galaxies8-12 and companions of rare quasars13,14. These studies conclude that the contribution of dust-obscured galaxies to the cosmic star formation rate density at z > 6 is sub-dominant. Recent ALMA and Spitzer observations have identified a more abundant, less extreme population of obscured galaxies at z = 3-6 (refs. 15,16). However, this population has not been confirmed in the reionization epoch so far. Here, we report the discovery of two dust-obscured star-forming galaxies at z = 6.6813 ± 0.0005 and z = 7.3521 ± 0.0005. These objects are not detected in existing rest-frame UV data and were discovered only through their far-infrared [C II] lines and dust continuum emission as companions to typical UV-luminous galaxies at the same redshift. The two galaxies exhibit lower infrared luminosities and star-formation rates than extreme starbursts, in line with typical star-forming galaxies at z ≈ 7. This population of heavily dust-obscured galaxies appears to contribute 10-25% to the z > 6 cosmic star formation rate density.

A candidate redshift z ≈ 10 galaxy and rapid changes in that population at an age of 500 Myr.

Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900-2,000 million years (Myr) after the Big Bang (redshifts 6 > z > 3; ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z ≈ 8 galaxies that, together with reports of a γ-ray burst at z ≈ 8.2 (refs 10, 11), constitute the earliest objects reliably reported to date. Observations of z ≈ 7-8 galaxies suggest substantial star formation at z > 9-10 (refs 12, 13). Here we use the full two-year HUDF09 data to conduct an ultra-deep search for z ≈ 10 galaxies in the heart of the reionization epoch, only 500 Myr after the Big Bang. Not only do we find one possible z ≈ 10 galaxy candidate, but we show that, regardless of source detections, the star formation rate density is much smaller (∼10%) at this time than it is just ∼200 Myr later at z ≈ 8. This demonstrates how rapid galaxy build-up was at z ≈ 10, as galaxies increased in both luminosity density and volume density from z ≈ 10 to z ≈ 8. The 100-200 Myr before z ≈ 10 is clearly a crucial phase in the assembly of the earliest galaxies.

Síndrome de Miller Fisher: a propósito de un caso clínico / Miller Fisher syndrome: apropos of clinical case

INTRODUCCIÓN: El síndrome de Miller Fisher es la variante más frecuente del síndrome de Guillain Barré, llegando a una prevalencia del 5 por ciento de entre todas sus variantes. Fue descrito por Charles Miller Fisher en 1956, quien lo expuso como una variante inusual de una polineuritis idiopática aguda. Se caracteriza por la presentación aguda de una polineuropatía, asociada a la tríada de oftalmoplejía, ataxia y arreflexia; pudiendo progresar a un compromiso respiratorio con riesgo vital. PRESENTACIÓN DEL CASO: En el siguiente artículo, se expone el caso clínico de un paciente pesquisado en una revisión retrospectiva de los egresos del servicio de neurología del Hospital Clínico Herminda Martin, el que fue diagnosticado como síndrome de MillerFisher. Se trata del caso de un paciente varón de 77 años, con antecedentes de cardiopatía no precisada e hipercolesterolemia, que se presenta en policlínico de neurología con disartria, ataxia, paraparesia y oftalmoplejía. DISCUSIÓN: Se realizará un análisis contrastado entre la presentación, evolución, tratamiento y datos pesquisados durante su estadía, en relación al manejo y características encontradas en la bibliografía consultada.

INTRODUCTION: Miller Fisher syndrome is the most common variant of Guillain Barré syndrome, reaching a prevalence of 5 percent among all its variants. It was described by Charles Miller Fisherin 1956, who exposed him as an unusual variant of acute inflammatory demyelinating polyneuropathy. It is characterized by acute onset of polyneuropathy, associated with the triad of ophthalmoplegia, ataxia and areflexia, and may progress to life-threatening respiratory compromise. CASE REPORT: The following article presents a case of a patient researched in a retrospective review of the hospital discharges of the department of neurology of Hospital Clínico Herminda Martin, who was diagnosed as Miller Fisher syndrome. This is the case of a 77years old male patient with a history of unspecified coronary heart disease, and hypercholesterolemia, who was presented in the emergency unit with dysarthria, ataxia, paraparesis and ophthalmoplegia. DISCUSSION: We will make an analysis contrast between the presentation, treatment and data collected made during his stay, in relation to the handling and features found in the literature.