SUMMARY / RELATED TOPICS

386BSD

386BSD is a discontinued Unix-like operating system based on the Berkeley Software Distribution. It was released in 1992 and ran on PC-compatible computer systems based on the 32-bit Intel 80386 microprocessor. 386BSD innovations included role-based security, ring buffers, self-ordered configuration and modular kernel design. 386BSD was written by Berkeley alumni Lynne Jolitz and William Jolitz. William Jolitz had considerable experience with prior BSD releases while at the University of California at Berkeley and both contributed code developed at Symmetric Computer Systems during the 1980s, to Berkeley. Work on porting 4.3BSD-Reno and 4.3BSD Net/2 to the Intel 80386 was done for the University of California by William Jolitz at Berkeley. 4.3BSD Net/2 was an incomplete non-operational release, with portions withheld by the University of California as encumbered. The 386BSD releases made to the public beginning in 1992 were based on portions of the 4.3BSD Net/2 release coupled with additional code written by William and Lynne Jolitz to make a complete operational release.

The port began in 1989 and the first, incomplete traces of the port can be found in 4.3BSD Net/2 of 1991. The port was made possible as Keith Bostic influenced by Richard Stallman, had started to remove proprietary AT&T out of BSD in 1988; the port was first released in March 1992 and in a much more usable version on July 14, 1992. The porting process with code was extensively documented in an 18-part series written by Lynne Jolitz and William Jolitz in Dr. Dobb's Journal beginning in January 1991. After the release of 386BSD 0.1, a group of users began collecting bug fixes and enhancements, releasing them as an unofficial patchkit. Due to differences of opinion between the Jolitzes and the patchkit maintainers over the future direction and release schedule of 386BSD, the maintainers of the patchkit founded the FreeBSD project in 1993 to continue their work. Around the same time, the NetBSD project was founded by a different group of 386BSD users, with the aim of unifying 386BSD with other strands of BSD development into one multi-platform system.

Both projects continue to this day. Due to a lawsuit, some so-called encumbered source was agreed to have been distributed within the Berkeley Software Distribution Net/2 from the University of California, a subsequent release was made by the University to correct this issue. However, 386BSD, Dr. Dobb's Journal, William Jolitz and Lynne Jolitz were never parties to these or subsequent lawsuits or settlements arising from this dispute with the University of California, continued to publish and work on the 386BSD code base before and after these lawsuits without limitation. There has never been any legal filings or claims from the University, USL, or other responsible parties with respect to 386BSD. No code developed for 386BSD done by William Jolitz and Lynne Jolitz was at issue in any of these lawsuits. In late 1994, a finished version 386BSD Release 1.0 was distributed by Dr. Dobb's Journal on CDROM only due to the immense size of the release and was a best-selling CDROM for three years. 386BSD Release 1.0 contained a new kernel design and implementation, began the process to incorporate recommendations made by earlier Berkeley designers that had never been attempted in BSD.

On August 5, 2016 an update was pushed to the 386BSD github by developer Ben Jolitz, named version 2.0. Release 2.0 built upon the modular framework to create self-healing components. However, as of March 16, 2017 all of the documentation remains the same as version 1.0, a change log was not available. 386BSD is confused with BSD/386, a different project developed by BSDi, a Berkeley spinout, starting in 1991. BSD/386 used the same 386BSD code contributed to the University of California on 4.3BSD NET/2. Although Jolitz worked for UUNET in 1991, the work he did for them diverged from that contributed to the University of California and did not appear in 386BSD. Instead, William Jolitz gave regular code updates to Donn Seeley of BSDi for packaging and testing, returned all materials when William Jolitz left that company following fundamental disagreements on company direction and goals. All rights with respect to 386BSD and JOLIX are now held by William Jolitz and Lynne Jolitz. 386BSD public releases ended in 1997 since code is now available from the many 386BSD-derived operating systems today, along with several derivatives thereof.

Portions of 386BSD may be found in other open systems such as OpenSolaris. Jolitz, William F. and Jolitz, Lynne Greer: Porting UNIX to the 386: A Practical Approach, 17-part series in Dr. Dobb's Journal, January 1991 – July 1992:Jan/1991: DDJ "Designing a Software Specification" Feb/1991: DDJ "Three Initial PC Utilities" Mar/1991: DDJ "The Standalone System" Apr/1991: DDJ "Language Tools Cross-Support" May/1991: DDJ "The Initial Root Filesystem" Jun/1991: DDJ "Research and the Commercial Sector: Where Does BSD Fit In?" Jul/1991: DDJ "A Stripped-Down Kernel" Aug/1991: DDJ "The Basic Kernel" Sep/1991: DDJ "Multiprogramming and Multiprocessing, Part I" Oct/1991: DDJ "Multiprogramming and Multiprocessing, Part II" Nov/1991: DDJ "Device Autoconfiguration" Feb/1992: DDJ "UNIX Device Drivers, Part I" Mar/1992: DDJ "UNIX Device Drivers, Part II" Apr/1992: DDJ "UNIX Device Drivers, Part III" May/1992: DDJ "Missing Pieces, Part I" Jun/1992: DDJ "Missing Pieces, Part II"

Mesentery

The mesentery is an organ that attaches the intestines to the posterior abdominal wall in humans and is formed by the double fold of peritoneum. It helps in storing fat and allowing blood vessels and nerves to supply the intestines, among other functions; the mesocolon was thought to be a fragmented structure, with all named parts—the ascending, transverse and sigmoid mesocolons, the mesoappendix, the mesorectum—separately terminating their insertion into the posterior abdominal wall. However, in 2012, new microscopic and electron microscopic examinations at the University of Limerick showed the mesocolon to be a single structure derived from the duodenojejunal flexure and extending to the distal mesorectal layer. Thus, the mesentery is an internal organ; the mesentery of the small intestine arises from the root of the mesentery and is the part connected with the structures in front of the vertebral column. The root is narrow, about 15 cm long, 20 cm in width, is directed obliquely from the duodenojejunal flexure at the left side of the second lumbar vertebra to the right sacroiliac joint.

The root of the mesentery extends from the duodenojejunal flexure to the ileocaecal junction. This section of the small intestine is located centrally in the abdominal cavity and lies behind the transverse colon and the greater omentum; the mesentery becomes attached to the colon at the gastrointestinal margin and continues as the several regions of the mesocolon. The parts of the mesocolon take their names from the part of the colon; these are the transverse mesocolon attaching to the transverse colon, the sigmoid mesocolon attaching to the sigmoid colon, the mesoappendix attaching to the appendix, the mesorectum attaching to the upper third of the rectum. The mesocolon regions were traditionally taught to be separate sections with separate insertions into the posterior abdominal wall. In 2012, the first detailed observational and histological studies of the mesocolon were undertaken and this revealed several new findings; the study included 109 patients undergoing open, total abdominal colectomy.

Anatomical observations were recorded on the post-operative specimens. These studies showed, it was shown that a mesenteric confluence occurs at the ileocaecal and rectosigmoid junctions, as well as at the hepatic and splenic flexures and that each confluence involves peritoneal and omental attachments. The proximal rectum was mesosigmoid. A plane occupied by perinephric fascia was shown to separate the entire apposed small intestinal mesentery and the mesocolon from the retroperitoneum. Deep in the pelvis, this fascia coalesces to give rise to presacral fascia. Flexural anatomy is described as a difficult area, it is simplified. The ileocaecal flexure arises at the point where the ileum is continuous with the caecum around the ileocaecal mesenteric flexure; the hepatic flexure is formed between the right mesocolon and transverse mesocolon at the mesenteric confluence. The colonic component of the hepatic flexure is draped around this mesenteric confluence. Furthermore, the splenic flexure is formed by the mesenteric confluence between the transverse and left mesocolon.

The colonic component of the splenic flexure occurs lateral to the mesenteric confluence. At every flexure, a continuous peritoneal fold lies outside the colonic/mesocolic complex tethering this to the posterior abdominal wall; the transverse mesocolon is that section of the mesocolon attached to the transverse colon that lies between the colic flexures. The sigmoid mesocolon is that region of the mesentery to which the sigmoid colon is attached at the gastrointestinal mesenteric margin; the mesoappendix is the portion of the mesocolon connecting the ileum to the appendix. It may extend to the tip of the appendix, it encloses the appendicular artery and vein, as well as lymphatic vessels, a lymph node. The mesorectum is that part attached to the upper third of the rectum. Understanding the macroscopic structure of the mesenteric organ meant that associated structures—the peritoneal folds and congenital and omental adhesions—could be better appraised; the small intestinal mesenteric fold occurs where the small intestinal mesentery folds onto the posterior abdominal wall and continues laterally as the right mesocolon.

During mobilization of the small intestinal mesentery from the posterior abdominal wall, this fold is incised, allowing access to the interface between the small intestinal mesentery and the retroperitoneum. The fold continues at the inferolateral boundary of the ileocaecal junction and turn cephalad as the right paracolic peritoneal fold; this fold is divided during lateral to medial mobilization, permitting the surgeon to serially lift the right colon and associated mesentery off the underlying fascia and retroperitoneum. At the hepatic flexure, the right lateral peritoneal fold turns and continues medially as the hepatocolic peritoneal fold. Division of the fold in this location permits separation of the colonic component of the hepatic flexure and mesocolon off the retroperitoneum. Interposed between the hepatic and splenic flexures, the greater omentum adheres to the transverse colon along a further band or fold of peritoneum. Dissection through this allows access to the cephalad surface of the transverse mesocolon.

Focal adhesions tether the greater omentum to the cephalad aspect of the transverse mesocolon. The left colon is associated with a similar anatomic configuration of peritoneal folds.

Andorra–La Seu d'Urgell Airport

Andorra–La Seu d'Urgell Airport is a public airport owned by the Government of Catalonia and hosts general aviation and commercial flights. It is located in the municipality of Montferrer i Castellbò in Catalonia, eastern Spain, serves the city of la Seu d'Urgell and the microstate Principality of Andorra, 12 km north of the airport; the airport has a short runway which limits the distance to destinations. La Seu d'Urgell airfield opened in 1982 but was closed to commercial traffic in 1984 and was used only by private aircraft until 2008, when the airport was purchased by the Catalan government and closed pending its redevelopment and reopening as a commercial airport. In 2008, the Institut Català del Sòl bought 85% of the airport's land to create Pirineus–La Seu d'Urgell Airport. In 2009, a contract was awarded to Acsa Sorigué for the redevelopment work towards reopening the airport; the airport reopened on 4 June 2010. In the first year there was a total of 1,751 flights, with more than 3,000 people on board.

An agreement between the Catalan government and the Principality of Andorra, located 12 km away, was reached in 2014 to rename the facility Andorra–La Seu d'Urgell Airport following financial investment from Andorra. On 8 January 2015 the airport opened as a public airport, started receiving regular or tourist charter flights during 2015. Eight tourist charter flights per direction were operated by Swiftair during the summer 2015, four from Madrid, four from Palma de Mallorca. 2015 saw the arrival of Air Andorra and Andorra Airlines, with both airlines using the airport as its main hub and offering flights to various airports in Spain and France. French regional airline Twin Jet operated flights to the airport during March 2018, with routes from Madrid and Palma de Mallorca; as of 11 July 2018, there are no regular commercial flights at the airport. Andorra–La Seu d'Urgell Airport