Memory CD4 T cell subsets are kinetically heterogeneous and replenished from naive T cells at high levels

Characterising the longevity of immunological memory requires establishing the rules underlying the renewal and death of peripheral T cells. However, we lack knowledge of the population structure and how self-renewal and de novo influx contribute to maintenance of memory compartments. Here, we characterise the kinetics and structure of murine CD4 T cell memory subsets by measuring the rates of influx of new cells and using detailed timecourses of DNA labelling that also distinguish the behaviour of recently divided and quiescent cells. We find that both effector and central memory CD4 T cells comprise subpopulations with highly divergent rates of turnover, and show that inflows of new cells sourced from the naive pool strongly impact estimates of memory cell lifetimes and division rates. We also demonstrate that the maintenance of CD4 T cell memory subsets in healthy mice is unexpectedly and strikingly reliant on this replenishment

Haemorrhoidal artery ligation compared to alternative surgical techniques for the treatment of grade II-IV haemorrhoids: A systematic review

Background. Haemorrhoidal disease is a common disorder in the Western World that commonly requires surgical treatment, but original open techniques were associated with significant complications and pain. Haemorrhoidal Arterial Ligation (HAL) has gained popularity for relatively low complication and postoperative pain rates. This review assesses clinical outcomes of this technique in comparison to alternative modern techniques. Methods. The literature was searched on MEDLINE, EMBASE, Google Scholar, and Cochrane Library databases. Search terms: dearterialization, artery ligation, mucopexy, recto-anal repair. Inclusion criteria: RCTs, original publications, grade II, III and/or grade IV haemorrhoids, elective procedures. Exclusion criteria: non-English, non-adults, published pre-2016. Results. 14 RCTs were included in the systematic review. HAL performed poorly in terms of recurrence, with a pooled recurrence rate of 10.34% for grade III haemorrhoids. HAL had a similar recurrence rate to Procedure for Prolapse and Haemorrhoids. Pain was comparable between groups. Conclusion. HAL is a safe surgical technique for the treatment of grade II to grade IV haemorrhoids. It still has a relatively low complication rate, and pain scores are comparable to other non-invasive techniques, and superior to open techniques. HAL still performs poorly in terms of recurrence rates. New modified procedures including suture-mucopexy only and tissue-selecting techniques appear to have better therapeutic potential

Uncertainty Principles and Balian-Low type Theorems in Principal Shift-Invariant Spaces

In this paper, we consider the time-frequency localization of the generator of a principal shift-invariant space on the real line which has additional shift-invariance. We prove that if a principal shift-invariant space on the real line is translation-invariant then any of its orthonormal (or Riesz) generators is non-integrable. However, for any $n\ge2$, there exist principal shift-invariant spaces on the real line that are also \nZ-invariant with an integrable orthonormal (or a Riesz) generator $\phi$, but $\phi$ satisfies $\int_{\mathbb R} |\phi(x)|^2 |x|^{1+\epsilon} dx=\infty$ for any $\epsilon>0$ and its Fourier transform $\hat\phi$ cannot decay as fast as $(1+|\xi|)^{-r}$ for any $r>1/2$. Examples are constructed to demonstrate that the above decay properties for the orthormal generator in the time domain and in the frequency domain are optimal

Magnetic order and the electronic ground state in the pyrochlore iridate Nd2Ir2O7

We report a combined muon spin relaxation/rotation, bulk magnetization, neutron scattering, and transport study of the electronic properties of the pyrochlore iridate Nd2Ir2O7. We observe the onset of strongly hysteretic behavior in the temperature dependent magnetization below 120 K, and an abrupt increase in the temperature dependent resistivity below 8 K. Zero field muon spin relaxation measurements show that the hysteretic magnetization is driven by a transition to a magnetically disordered state, and that below 8 K a complex magnetically ordered ground state sets in, as evidenced by the onset of heavily damped spontaneous muon precession. Our measurements point toward the absence of a true metal-to-insulator phase transition in this material and suggest that Nd2Ir2O7 lies either within or on the metallic side of the boundary of the Dirac semimetal regime within its topological phase diagram.Comment: 21 pages, 7 figure

A comparative framework: how broadly applicable is a 'rigorous' critical junctures framework?

The paper tests Hogan and Doyle's (2007, 2008) framework for examining critical junctures. This framework sought to incorporate the concept of ideational change in understanding critical junctures. Until its development, frameworks utilized in identifying critical junctures were subjective, seeking only to identify crisis, and subsequent policy changes, arguing that one invariably led to the other, as both occurred around the same time. Hogan and Doyle (2007, 2008) hypothesized ideational change as an intermediating variable in their framework, determining if, and when, a crisis leads to radical policy change. Here we test this framework on cases similar to, but different from, those employed in developing the exemplar. This will enable us determine whether the framework's relegation of ideational change to a condition of crisis holds, or, if ideational change has more importance than is ascribed to it by this framework. This will also enable us determined if the framework itself is robust, and fit for the purposes it was designed to perform — identifying the nature of policy change