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The inner $\sim$200 pc region of the Galaxy contains a 4 million M$_{\odot}$ supermassive black hole (SMBH), significant quantities of molecular gas, and star formation and cosmic ray energy densities that are roughly two orders of magnitude higher than the corresponding levels in the Galactic disk. At a distance of only 8.2 kpc, the region presents astronomers with a unique opportunity to study a diverse range of energetic astrophysical phenomena, from stellar objects in extreme environments, to the SMBH and star-formation driven feedback processes that are known to influence the evolution of galaxies as a whole. We present a new survey of the Galactic center conducted with the South African MeerKAT radio telescope. Radio imaging offers a view that is unaffected by the large quantities of dust that obscure the region at other wavelengths, and a scene of striking complexity is revealed. We produce total intensity and spectral index mosaics of the region from 20 pointings (144 hours on-target in total), covering 6.5 square degrees with an angular resolution of 4$"$,at a central frequency of 1.28 GHz. Many new features are revealed for the first time due to a combination of MeerKAT's high sensitivity, exceptional $u,v$-plane coverage, and geographical vantage point. We highlight some initial survey results, including new supernova remnant candidates, many new non-thermal filament complexes, and enhanced views of the Radio Arc Bubble, Sgr A and Sgr B regions. This project is a SARAO public legacy survey, and the image products are made available with this article., Comment: 29 pages, 15 figures, 3 tables, accepted for publication in the The Astrophysical Journal. Replacement arXiv version with higher quality figures

MeerKAT's large number of antennas, spanning 8 km with a densely packed 1 km core, create a powerful instrument for wide-area surveys, with high sensitivity over a wide range of angular scales. The MeerKAT Galaxy Cluster Legacy Survey (MGCLS) is a programme of long-track MeerKAT L-band (900-1670 MHz) observations of 115 galaxy clusters, observed for $\sim$6-10 hours each in full polarisation. The first legacy product data release (DR1), made available with this paper, includes the MeerKAT visibilities, basic image cubes at $\sim$8" resolution, and enhanced spectral and polarisation image cubes at $\sim$8" and 15" resolutions. Typical sensitivities for the full-resolution MGCLS image products are $\sim$3-5 {\mu}Jy/beam. The basic cubes are full-field and span 4 deg^2. The enhanced products consist of the inner 1.44 deg^2 field of view, corrected for the primary beam. The survey is fully sensitive to structures up to $\sim$10' scales and the wide bandwidth allows spectral and Faraday rotation mapping. HI mapping at 209 kHz resolution can be done at $0, Comment: 43 pages, 33 figures, 6 tables. Accepted for publication in Astronomy and Astrophysics

This chapter by G.H. Bennett argues that in the historiography of D-Day there has been a failure to analyze and understand the inability of German coastal forces to contest the invasion more effectively. The outcome of the naval battles off the Normandy coast was not the inevitable result of Allied material superiority. In the the development of German naval strategy since 1870, the Kriegsmarine reached a moment of strategic choice in the spring of 1943. It could either continue to try and fight an oceanic tonnage war, or to pursue a strategy of coastal defense of the German empire in the west. There was a failure to accept, articulate, and imaginatively manage the strategy of coastal defense that might have given the German Army more of a chance on 6 June and the days thereafter. Much of this failure can be put on Admiral Dönitz, although it was also structural. However, the performance of German coastal forces against the Allied invasion flotilla was more significant than has been recognized by historians, serving as an indicator of the greater successes that might have been achieved if a strategy of littoral defense had been adopted.

We present the confusion-limited 1.28 GHz MeerKAT DEEP2 image covering one $\approx 68'$ FWHM primary beam area with $7.6''$ FWHM resolution and $0.55 \pm 0.01$ $\mu$Jy/beam rms noise. Its J2000 center position $\alpha=04^h 13^m 26.4^s$, $\delta=-80^\circ 00' 00''$ was selected to minimize artifacts caused by bright sources. We introduce the new 64-element MeerKAT array and describe commissioning observations to measure the primary beam attenuation pattern, estimate telescope pointing errors, and pinpoint $(u,v)$ coordinate errors caused by offsets in frequency or time. We constructed a 1.4 GHz differential source count by combining a power-law count fit to the DEEP2 confusion $P(D)$ distribution from $0.25$ to $10$ $\mu$Jy with counts of individual DEEP2 sources between $10$ $\mu$Jy and $2.5$ mJy. Most sources fainter than $S \sim 100$ $\mu$Jy are distant star-forming galaxies obeying the FIR/radio correlation, and sources stronger than $0.25$ $\mu$Jy account for $\sim93\%$ of the radio background produced by star-forming galaxies. For the first time, the DEEP2 source count has reached the depth needed to reveal the majority of the star formation history of the universe. A pure luminosity evolution of the 1.4 GHz local luminosity function consistent with the Madau & Dickinson (2014) model for the evolution of star-forming galaxies based on UV and infrared data underpredicts our 1.4 GHz source count in the range $-5 \lesssim \log[S(\mathrm{Jy})] \lesssim -4$., Comment: 20 pages, 18 figures. Accepted for publication in ApJ

Diabetic retinopathy is a significant complication of diabetes, and the most common cause of blindness in people under the age of 65. The National Diabetic Retinal Screening Programme (Diabetic RetinaScreen) was established to detect sight threatening retinopathies. The purpose of this cross-sectional study is to determine the barriers to the uptake of Diabetic RetinaScreen, to investigate discrepancies in attendance, if any, between patients whose diabetes care is delivered in a large tertiary referral hospital out-patient setting or in general practice, and to evaluate general practitionerapos;s satisfaction with the service. Older age (OR 1.023, 95% CI 1.001 to 1.046) and complications of diabetes, excluding ocular complications, (OR 2.741, 95% CI 1.158 to 6.489) were associated with increased attendance at Diabetic RetinaScreen. Online referral is now available and the preferred method of referral. Efforts to encourage younger patients who do not yet have complications of diabetes may be beneficial.

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation., Comment: Published in ApJ (2018 April 5); 13 pages, 4 figures

This article examines the processes of displacement and dislocation for the aircrew that came together in 1940–42 to form the Forces aeriennes francaises libres (FAFL). It uses quantitative and qua...

Friedrich Jeckeln as Higher SS and Police Fuehrer for South Russia in 1941, and then North Russia from 1941 to 1944, was a key player in the development of the Holocast in the occupied Soviet Union. This article explores his career and motivations through the medium of his interrogation reports. Those interrogations were conducted by the NKVD from December 1945 to January 1946. They formed a key part in the development of a case against Jeckeln for involvement in crimes against the Soviet people. Using a variety of coercive techniques Jeckeln’s captors forced him to confront the enormity of his crimes. He was brought before a court and executed on the same day in February 1946.

After lunch the results of the West Derbyshire by-election came through: Lord Hartington lost to Mr White, the Independent, by 4,500 votes. This caused a pall of the blackest gloom to fallon the P.M. who is personally afflicted by this emphatic blow to the Government … Sitting in a chair in his study at the annexe, the P.M. looked old, tired and very depressed and was even muttering about a general election. Now, he said, with great events pending, was the time when national unity was essential: the question of annihilating great states had to be faced: it began to look as if democracy had not the persistence necessary to go through with it, however well it might have shown its capacity for defence.

The period 1919–24 saw fundamental change to the orientations of British foreign policy. In 1919 Britain was effectively at war with Russia: by 1924 a limited trade flowed between the two countries. Britain had fought a war against Germany from 1914 to 1918, imposed a harsh peace settlement upon her in 1919, and then spent the following years trying to revise that settlement. Indeed, by 1923 Britain was trying to curb the excesses of her Entente partner against Germany. Lloyd George and Curzon had been determined to impose the vindictive Treaty of Sevres on a prostrate Turkey in 1920: by 1923 Curzon was trying to negotiate a settlement with Ismet Pasha as an equal party. In 1920 Britain had accepted responsibility for Iraq and Palestine, and had then spent the next three years debating whether those responsibilities could be abdicated. In 1918 the British Empire appeared triumphant and supreme. Her world authority had seemingly been confirmed and enhanced by the defeat of Germany. By 1922 it was apparent that Britain did not possess the means or influence to mould the postwar world to her own desiderata. Moreover, the United States was emerging ever more prominently as the heir to Britain’s global predominance.

The most contentious policy area facing Curzon and Lloyd George in October 1919 was relations with Soviet Russia. The Bolshevik government had signed a Russo-German armistice in December 1917. Three months later, the landing of 130 Royal Marines at Murmansk, to protect vast quantities of war material supplied by the Allies, signalled the start of an Allied intervention in Russian affairs. By December 1918 Anglo-Soviet relations were deteriorating rapidly and, with the collapse of the Central Powers, the intervention had lost its ostensible raison d’etre. Some 30 000 Allied troops were established in north Russia and Siberia, and were developing a presence in Russian Central Asia, where local anti-Bolshevik regimes had emerged. Increasingly these troops were used in support of White Russian forces seeking to overthrow the Bolshevik regime.

On 25 October 1919 Churchill submitted a memorandum to the Cabinet calling into question the vindictive nature of Britain’s policy towards Turkey since the armistice.1 He noted that the signature of a Turkish peace treaty was still a distant prospect. Furthermore, the maintenance of sufficient forces in Egypt, Iraq and Palestine to guard against an attack by the nationalist forces of Mustapha Kemal, the Turkish general who had taken up arms against the Allies and the Sultan’s government at Constantinople in defence of the Anatolian Turkish heartland, was creating a heavy burden on the War Office estimates. Churchill’s bold suggestions would have amounted to a wholesale revision of Allied policy, including the renunciation of their individual territorial claims in favour of the League of Nations. Thus Britain would have given up responsibility for Palestine and Iraq. Rather than implying an earnest desire for moderate treatment of the defeated Turks, Churchill’s ideas reflected his growing suspicion that British policy towards Asia Minor might not ultimately be in her own best interests, and that Kemalist resistance to a harsh peace might lead to renewed warfare.

The area of Europe covering France, Germany and the Low Countries was regarded as the key theatre of postwar British diplomacy. It was on this arena that the eyes of the British government and Foreign Office chiefly focused. As a result of wartime news coverage, the appalling casualty lists and, in many cases, personal experience of service overseas, the British people had acquired a raised awareness and knowledge of foreign affairs which was based on a keen perception that ‘foreign policy kills’. British policy towards western Europe thus had a domestic political dimension which Lloyd George for one appreciated. ‘The man who won the war’ was determined to reap an electoral harvest as ‘the man who won the peace’. Above all, the policy-makers wished to prevent any renewal of armed conflict in western Europe into which Britain might be drawn. Implementation by Germany of the Treaty of Versailles was an important British security concern. Europe, and France in particular, had to be spared a German war of revenge. This danger formed ‘the German problem’, and Franco-German relations constituted an essential issue for the long-term peace of Europe. Maintenance of the Anglo-French Entente and harmony of policy were vital components of the postwar settlement. The retreat of the United States into political isolation in late 1919 placed the burden of upholding the Treaty of Versailles firmly on to the shoulders of Britain and France. By 1921, however, Anglo-French relations had deteriorated to a serious extent.

As a result of the war and the subsequent peace settlement Scandinavia, eastern Europe and the Balkans emerged as a cordon sanitaire through which it was hoped a resurgence of German, Russian and Turkish power would be checked. The Baltic States, Poland, Czechoslovakia, Roumania, Italy and Yugoslavia formed a politically unstable and divided ring bordering the defeated Central Powers of Germany, Austria, Hungary and Bulgaria. Along with Scandinavia, they also served as a politicomilitary firebreak against the spread of Bolshevism from Russia. The European states which emerged as a result of the war were anti-Bolshevik and had their own territorial ambitions on the lands of the former Russian Empire. They eyed one another with a mixture of jealousy and suspicion which made eastern Europe a new breeding ground for war. In the Far East Japan, Britainx’s ally since 1902, acted as a further element in the cordon, which was complemented by the British presence in Iraq, Persia, India, and in 1919 in the Trans-Caspian and Trans-Caucasian regions.

Britain’s policy towards Persia was closely linked to the development of Britain’s Empire in the Arab Middle East. The policy-makers hoped that Persia would form an informal extension to the Middle East mandates, so that Britain’s Asian Empire would stretch from Palestine to the Burma/Thailand border. As with Afghanistan, the importance of Persia for the security of the British Empire had long been recognised, and attempts to increase British influence there had led to a dangerous rivalry with Russia’s ambitions.

Friesian cows were inseminated with semen mixtures containing equal numbers of spermatozoa from a Friesian and a Hereford bull. The five bulls of each breed gave twenty-five possible combinations. The paternity of calves was established by inspection of colour and conformation. Heterospermic indices were calculated to express the relative ability of sires to father offspring after mixed insemination. There were significant differences between the heterospermic indices of bulls, the maximum observed difference being twenty-one-fold. The indices were consistent over two series. The homospermic index was defined as the 16-week non-return rate after normal single first inseminations. The heterospermic index established differences between bulls more efficiently than the homospermic index; one estimate showed that the heterospermic method needed less than 1/170th the number of inseminations required by the homospermic method. The homospermic index was predictable from the heterospermic index, the regression coefficient having a significance level of 0\m=.\05> P > 0\m=.\025.The initial spermatozoan concentration of a bull's semen (before dilution) was highly correlated with the heterospermic index. Measures of semen quality based on the morphology and staining affinity of spermatozoa predicted heterospermic and homospermic indices non-significantly but in the right direction.

The technique of storing bull semen at -79° C. in the presence of glycerol has become widely practised in recent years, and the usefulness of the method was increased when Joyner (1954) showed that Trichomonas foetus could be eliminated from infected semen by subjecting it to a freezing process similar to that used for the preservation of spermatozoa. Exceptional sensitivity of this agellate to freezing was confirmed by McEntegart (1954), who found that while other species of Trichornonas survived the freezing and thawing process T. foetus was killed. A number of other workers, however, ha,ve reported the recovery of T. foetus after freezing to-79° C., but in every case the methods used differed from that followed by Joyner (1954). Accordingly, it was evident that the freezing method could not be relied upon to eliminate the parasites until it was known which modifications in technique permitted the protozoa to survive. The first experiments described in this paper were carried out to confirm that T. foetus in semen did not survive freezing and thawing in egg-yolk citrate as originally described (Joyner, 1954), with the added precaution of assessing the viability of the spermatozoa before and after freezing, by the eosin vital staining technique. From the literature it seemed likely that some modifications in the suspending medium might permit the survival of the protozoa. Thus, in their freezing experiments from which T. foettxs wa.s recovered, Levine & Marquardt (1955) used cysteine-peptone-liver infusion-maltose (a.P.L.M.) medium with 5-10% glycerol, and Leidl & Mahrla (1954) used serum broth with 10% glycerol. McWade & WiSliams (1954) demonstrated the survival of T. foetus in a milk semen diluent containing 7 °/O glycerol. All these suspending media diSered from the egg-yolkcitrate semen-diluent with 10% glycerol in which the trichomonads did not survive (Joyner, 1954). The second series of experiments was, therefore, designed to demonstrate the efEects of different diluents and varying concentrations of glycerol using trichomonads from cultures and preputial washings.